diff --git a/lib/specifications/Specification.js b/lib/specifications/Specification.js
index 60dbd969f..06f27feaa 100644
--- a/lib/specifications/Specification.js
+++ b/lib/specifications/Specification.js
@@ -120,7 +120,7 @@ class Specification {
 				this._log.verbose(err.message);
 				throw new Error(
 					`${config.kind} ${config.metadata.name} defines unsupported Specification Version ` +
-					`${originalSpecVersion}. Please manually upgrade to 2.0 or higher. ` +
+					`${originalSpecVersion}. Please manually upgrade to 3.0 or higher. ` +
 					`For details see https://sap.github.io/ui5-tooling/pages/Configuration/#specification-versions - ` +
 					`An attempted migration to a supported specification version failed, ` +
 					`likely due to unrecognized configuration. Check verbose log for details.`);
@@ -249,6 +249,9 @@ class Specification {
 	}
 
 	_migrateLegacyProject(config) {
+		// Stick to 2.6 since 3.0 adds further restrictions (i.e. for the name) and enables
+		// functionality for extensions that shouldn't be enabled if the specVersion is not
+		// explicitly set to 3.x
 		config.specVersion = "2.6";
 
 		// propertiesFileSourceEncoding (relevant for applications and libraries) default
diff --git a/lib/validation/schema/specVersion/kind/extension.json b/lib/validation/schema/specVersion/kind/extension.json
index c5c469100..2c673c508 100644
--- a/lib/validation/schema/specVersion/kind/extension.json
+++ b/lib/validation/schema/specVersion/kind/extension.json
@@ -70,6 +70,25 @@
 					"type": "string"
 				}
 			}
+		},
+		"metadata-3.0": {
+			"type": "object",
+			"required": ["name"],
+			"additionalProperties": false,
+			"properties": {
+				"name": {
+					"type": "string",
+					"minLength": 3,
+					"maxLength": 50,
+					"pattern": "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$",
+					"title": "Extension Name",
+					"description": "Unique identifier for the extension. E.g. ui5-task-fearless-rock",
+					"errorMessage": "Not a valid extension name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name"
+				},
+				"copyright": {
+					"type": "string"
+				}
+			}
 		}
 	}
 }
diff --git a/lib/validation/schema/specVersion/kind/extension/project-shim.json b/lib/validation/schema/specVersion/kind/extension/project-shim.json
index 4f3d9226c..415785f1d 100644
--- a/lib/validation/schema/specVersion/kind/extension/project-shim.json
+++ b/lib/validation/schema/specVersion/kind/extension/project-shim.json
@@ -6,14 +6,14 @@
 	"required": ["specVersion", "kind", "type", "metadata", "shims"],
 	"if": {
 		"properties": {
-			"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4", "2.5", "2.6", "3.0"] }
+			"specVersion": { "enum": ["3.0"] }
 		}
 	},
 	"then": {
 		"additionalProperties": false,
 		"properties": {
 			"specVersion": {
-				"enum": ["2.1", "2.2", "2.3", "2.4", "2.5", "2.6", "3.0"]
+				"enum": ["3.0"]
 			},
 			"kind": {
 				"enum": ["extension"]
@@ -22,7 +22,7 @@
 				"enum": ["project-shim"]
 			},
 			"metadata": {
-				"$ref": "../extension.json#/definitions/metadata"
+				"$ref": "../extension.json#/definitions/metadata-3.0"
 			},
 			"shims": {
 				"$ref": "#/definitions/shims"
@@ -34,22 +34,53 @@
 		}
 	},
 	"else": {
-		"additionalProperties": false,
-		"properties": {
-			"specVersion": {
-				"enum": ["2.0"]
-			},
-			"kind": {
-				"enum": ["extension"]
-			},
-			"type": {
-				"enum": ["project-shim"]
-			},
-			"metadata": {
-				"$ref": "../extension.json#/definitions/metadata"
-			},
-			"shims": {
-				"$ref": "#/definitions/shims"
+		"if": {
+			"properties": {
+				"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4", "2.5", "2.6"] }
+			}
+		},
+		"then": {
+			"additionalProperties": false,
+			"properties": {
+				"specVersion": {
+					"enum": ["2.1", "2.2", "2.3", "2.4", "2.5", "2.6"]
+				},
+				"kind": {
+					"enum": ["extension"]
+				},
+				"type": {
+					"enum": ["project-shim"]
+				},
+				"metadata": {
+					"$ref": "../extension.json#/definitions/metadata"
+				},
+				"shims": {
+					"$ref": "#/definitions/shims"
+				},
+				"customConfiguration": {
+					"type": "object",
+					"additionalProperties": true
+				}
+			}
+		},
+		"else": {
+			"additionalProperties": false,
+			"properties": {
+				"specVersion": {
+					"enum": ["2.0"]
+				},
+				"kind": {
+					"enum": ["extension"]
+				},
+				"type": {
+					"enum": ["project-shim"]
+				},
+				"metadata": {
+					"$ref": "../extension.json#/definitions/metadata"
+				},
+				"shims": {
+					"$ref": "#/definitions/shims"
+				}
 			}
 		}
 	},
diff --git a/lib/validation/schema/specVersion/kind/extension/server-middleware.json b/lib/validation/schema/specVersion/kind/extension/server-middleware.json
index 151c0c222..a65db5b56 100644
--- a/lib/validation/schema/specVersion/kind/extension/server-middleware.json
+++ b/lib/validation/schema/specVersion/kind/extension/server-middleware.json
@@ -7,13 +7,13 @@
 	"required": ["specVersion", "kind", "type", "metadata", "middleware"],
 	"if": {
 		"properties": {
-			"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4", "2.5", "2.6", "3.0"] }
+			"specVersion": { "enum": ["3.0"] }
 		}
 	},
 	"then": {
 		"additionalProperties": false,
 		"properties": {
-			"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4", "2.5", "2.6", "3.0"] },
+			"specVersion": { "enum": ["3.0"] },
 			"kind": {
 				"enum": ["extension"]
 			},
@@ -21,7 +21,7 @@
 				"enum": ["server-middleware"]
 			},
 			"metadata": {
-				"$ref": "../extension.json#/definitions/metadata"
+				"$ref": "../extension.json#/definitions/metadata-3.0"
 			},
 			"middleware": {
 				"$ref": "#/definitions/middleware"
@@ -33,20 +33,49 @@
 		}
 	},
 	"else": {
-		"additionalProperties": false,
-		"properties": {
-			"specVersion": { "enum": ["2.0"] },
-			"kind": {
-				"enum": ["extension"]
-			},
-			"type": {
-				"enum": ["server-middleware"]
-			},
-			"metadata": {
-				"$ref": "../extension.json#/definitions/metadata"
-			},
-			"middleware": {
-				"$ref": "#/definitions/middleware"
+		"if": {
+			"properties": {
+				"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4", "2.5", "2.6"] }
+			}
+		},
+		"then": {
+			"additionalProperties": false,
+			"properties": {
+				"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4", "2.5", "2.6"] },
+				"kind": {
+					"enum": ["extension"]
+				},
+				"type": {
+					"enum": ["server-middleware"]
+				},
+				"metadata": {
+					"$ref": "../extension.json#/definitions/metadata"
+				},
+				"middleware": {
+					"$ref": "#/definitions/middleware"
+				},
+				"customConfiguration": {
+					"type": "object",
+					"additionalProperties": true
+				}
+			}
+		},
+		"else": {
+			"additionalProperties": false,
+			"properties": {
+				"specVersion": { "enum": ["2.0"] },
+				"kind": {
+					"enum": ["extension"]
+				},
+				"type": {
+					"enum": ["server-middleware"]
+				},
+				"metadata": {
+					"$ref": "../extension.json#/definitions/metadata"
+				},
+				"middleware": {
+					"$ref": "#/definitions/middleware"
+				}
 			}
 		}
 	},
diff --git a/lib/validation/schema/specVersion/kind/extension/task.json b/lib/validation/schema/specVersion/kind/extension/task.json
index ab5413c78..f19291e0c 100644
--- a/lib/validation/schema/specVersion/kind/extension/task.json
+++ b/lib/validation/schema/specVersion/kind/extension/task.json
@@ -6,13 +6,13 @@
 	"required": ["specVersion", "kind", "type", "metadata", "task"],
 	"if": {
 		"properties": {
-			"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4", "2.5", "2.6", "3.0"] }
+			"specVersion": { "enum": ["3.0"] }
 		}
 	},
 	"then": {
 		"additionalProperties": false,
 		"properties": {
-			"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4", "2.5", "2.6", "3.0"] },
+			"specVersion": { "enum": ["3.0"] },
 			"kind": {
 				"enum": ["extension"]
 			},
@@ -20,7 +20,7 @@
 				"enum": ["task"]
 			},
 			"metadata": {
-				"$ref": "../extension.json#/definitions/metadata"
+				"$ref": "../extension.json#/definitions/metadata-3.0"
 			},
 			"task": {
 				"$ref": "#/definitions/task"
@@ -32,20 +32,49 @@
 		}
 	},
 	"else": {
-		"additionalProperties": false,
-		"properties": {
-			"specVersion": { "enum": ["2.0"] },
-			"kind": {
-				"enum": ["extension"]
-			},
-			"type": {
-				"enum": ["task"]
-			},
-			"metadata": {
-				"$ref": "../extension.json#/definitions/metadata"
-			},
-			"task": {
-				"$ref": "#/definitions/task"
+		"if": {
+			"properties": {
+				"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4", "2.5", "2.6"] }
+			}
+		},
+		"then": {
+			"additionalProperties": false,
+			"properties": {
+				"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4", "2.5", "2.6"] },
+				"kind": {
+					"enum": ["extension"]
+				},
+				"type": {
+					"enum": ["task"]
+				},
+				"metadata": {
+					"$ref": "../extension.json#/definitions/metadata"
+				},
+				"task": {
+					"$ref": "#/definitions/task"
+				},
+				"customConfiguration": {
+					"type": "object",
+					"additionalProperties": true
+				}
+			}
+		},
+		"else": {
+			"additionalProperties": false,
+			"properties": {
+				"specVersion": { "enum": ["2.0"] },
+				"kind": {
+					"enum": ["extension"]
+				},
+				"type": {
+					"enum": ["task"]
+				},
+				"metadata": {
+					"$ref": "../extension.json#/definitions/metadata"
+				},
+				"task": {
+					"$ref": "#/definitions/task"
+				}
 			}
 		}
 	},
diff --git a/lib/validation/schema/specVersion/kind/project.json b/lib/validation/schema/specVersion/kind/project.json
index 3d6a1a49b..3d8554584 100644
--- a/lib/validation/schema/specVersion/kind/project.json
+++ b/lib/validation/schema/specVersion/kind/project.json
@@ -93,6 +93,37 @@
 				}
 			}
 		},
+		"metadata-3.0": {
+			"type": "object",
+			"required": ["name"],
+			"additionalProperties": false,
+			"properties": {
+				"name": {
+					"type": "string",
+					"minLength": 3,
+					"maxLength": 50,
+					"pattern": "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$",
+					"title": "Project Name",
+					"description": "Unique identifier for the project. E.g. organization.product.project",
+					"errorMessage": "Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name"
+				},
+				"copyright": {
+					"type": "string"
+				},
+				"deprecated": {
+					"type": "boolean",
+					"default": false
+				},
+				"sapInternal": {
+					"type": "boolean",
+					"default": false
+				},
+				"allowSapInternal": {
+					"type": "boolean",
+					"default": false
+				}
+			}
+		},
 		"resources-configuration-propertiesFileSourceEncoding": {
 			"enum": ["UTF-8", "ISO-8859-1"],
 			"default": "UTF-8",
diff --git a/lib/validation/schema/specVersion/kind/project/application.json b/lib/validation/schema/specVersion/kind/project/application.json
index fd0b063c2..81073634a 100644
--- a/lib/validation/schema/specVersion/kind/project/application.json
+++ b/lib/validation/schema/specVersion/kind/project/application.json
@@ -20,7 +20,7 @@
 				"enum": ["application"]
 			},
 			"metadata": {
-				"$ref": "../project.json#/definitions/metadata"
+				"$ref": "../project.json#/definitions/metadata-3.0"
 			},
 			"framework": {
 				"$ref": "../project.json#/definitions/framework"
diff --git a/lib/validation/schema/specVersion/kind/project/library.json b/lib/validation/schema/specVersion/kind/project/library.json
index 86f1efe0a..d36a1f83e 100644
--- a/lib/validation/schema/specVersion/kind/project/library.json
+++ b/lib/validation/schema/specVersion/kind/project/library.json
@@ -20,7 +20,7 @@
 				"enum": ["library"]
 			},
 			"metadata": {
-				"$ref": "../project.json#/definitions/metadata"
+				"$ref": "../project.json#/definitions/metadata-3.0"
 			},
 			"framework": {
 				"$ref": "../project.json#/definitions/framework"
diff --git a/lib/validation/schema/specVersion/kind/project/module.json b/lib/validation/schema/specVersion/kind/project/module.json
index 8bd717ff5..9684f27d1 100644
--- a/lib/validation/schema/specVersion/kind/project/module.json
+++ b/lib/validation/schema/specVersion/kind/project/module.json
@@ -6,13 +6,13 @@
 	"required": ["specVersion", "type", "metadata"],
 	"if": {
 		"properties": {
-			"specVersion": { "enum": ["2.5", "2.6", "3.0"] }
+			"specVersion": { "enum": ["3.0"] }
 		}
 	},
 	"then": {
 		"additionalProperties": false,
 		"properties": {
-			"specVersion": { "enum": ["2.5", "2.6", "3.0"] },
+			"specVersion": { "enum": ["3.0"] },
 			"kind": {
 				"enum": ["project", null]
 			},
@@ -20,7 +20,7 @@
 				"enum": ["module"]
 			},
 			"metadata": {
-				"$ref": "../project.json#/definitions/metadata"
+				"$ref": "../project.json#/definitions/metadata-3.0"
 			},
 			"resources": {
 				"$ref": "#/definitions/resources"
@@ -40,13 +40,13 @@
 	"else": {
 		"if": {
 			"properties": {
-				"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4"] }
+				"specVersion": { "enum": ["2.5", "2.6"] }
 			}
 		},
 		"then": {
 			"additionalProperties": false,
 			"properties": {
-				"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4"] },
+				"specVersion": { "enum": ["2.5", "2.6"] },
 				"kind": {
 					"enum": ["project", null]
 				},
@@ -59,6 +59,12 @@
 				"resources": {
 					"$ref": "#/definitions/resources"
 				},
+				"builder": {
+					"$ref": "#/definitions/builder-specVersion-2.5"
+				},
+				"server": {
+					"$ref": "../project.json#/definitions/server"
+				},
 				"customConfiguration": {
 					"type": "object",
 					"additionalProperties": true
@@ -66,25 +72,53 @@
 			}
 		},
 		"else": {
-			"additionalProperties": false,
-			"properties": {
-				"specVersion": { "enum": ["2.0"] },
-				"kind": {
-					"enum": ["project", null]
-				},
-				"type": {
-					"enum": ["module"]
-				},
-				"metadata": {
-					"$ref": "../project.json#/definitions/metadata"
-				},
-				"resources": {
-					"$ref": "#/definitions/resources"
+			"if": {
+				"properties": {
+					"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4"] }
+				}
+			},
+			"then": {
+				"additionalProperties": false,
+				"properties": {
+					"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4"] },
+					"kind": {
+						"enum": ["project", null]
+					},
+					"type": {
+						"enum": ["module"]
+					},
+					"metadata": {
+						"$ref": "../project.json#/definitions/metadata"
+					},
+					"resources": {
+						"$ref": "#/definitions/resources"
+					},
+					"customConfiguration": {
+						"type": "object",
+						"additionalProperties": true
+					}
+				}
+			},
+			"else": {
+				"additionalProperties": false,
+				"properties": {
+					"specVersion": { "enum": ["2.0"] },
+					"kind": {
+						"enum": ["project", null]
+					},
+					"type": {
+						"enum": ["module"]
+					},
+					"metadata": {
+						"$ref": "../project.json#/definitions/metadata"
+					},
+					"resources": {
+						"$ref": "#/definitions/resources"
+					}
 				}
 			}
 		}
 	},
-
 	"definitions": {
 		"resources": {
 			"type": "object",
diff --git a/lib/validation/schema/specVersion/kind/project/theme-library.json b/lib/validation/schema/specVersion/kind/project/theme-library.json
index fc292179a..522b7064a 100644
--- a/lib/validation/schema/specVersion/kind/project/theme-library.json
+++ b/lib/validation/schema/specVersion/kind/project/theme-library.json
@@ -6,13 +6,13 @@
 	"required": ["specVersion", "type", "metadata"],
 	"if": {
 		"properties": {
-			"specVersion": { "enum": ["2.5", "2.6", "3.0"] }
+			"specVersion": { "enum": ["3.0"] }
 		}
 	},
 	"then": {
 		"additionalProperties": false,
 		"properties": {
-			"specVersion": { "enum": ["2.5", "2.6", "3.0"] },
+			"specVersion": { "enum": ["3.0"] },
 			"kind": {
 				"enum": ["project", null]
 			},
@@ -20,7 +20,7 @@
 				"enum": ["theme-library"]
 			},
 			"metadata": {
-				"$ref": "../project.json#/definitions/metadata"
+				"$ref": "../project.json#/definitions/metadata-3.0"
 			},
 			"framework": {
 				"$ref": "../project.json#/definitions/framework"
@@ -43,13 +43,13 @@
 	"else": {
 		"if": {
 			"properties": {
-				"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4"] }
+				"specVersion": { "enum": ["2.5", "2.6"] }
 			}
 		},
 		"then": {
 			"additionalProperties": false,
 			"properties": {
-				"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4"] },
+				"specVersion": { "enum": ["2.5", "2.6"] },
 				"kind": {
 					"enum": ["project", null]
 				},
@@ -66,7 +66,7 @@
 					"$ref": "library.json#/definitions/resources"
 				},
 				"builder": {
-					"$ref": "#/definitions/builder"
+					"$ref": "#/definitions/builder-specVersion-2.5"
 				},
 				"server": {
 					"$ref": "../project.json#/definitions/server"
@@ -78,34 +78,71 @@
 			}
 		},
 		"else": {
-			"additionalProperties": false,
-			"properties": {
-				"specVersion": { "enum": ["2.0"] },
-				"kind": {
-					"enum": ["project", null]
-				},
-				"type": {
-					"enum": ["theme-library"]
-				},
-				"metadata": {
-					"$ref": "../project.json#/definitions/metadata"
-				},
-				"framework": {
-					"$ref": "../project.json#/definitions/framework"
-				},
-				"resources": {
-					"$ref": "library.json#/definitions/resources"
-				},
-				"builder": {
-					"$ref": "#/definitions/builder"
-				},
-				"server": {
-					"$ref": "../project.json#/definitions/server"
+			"if": {
+				"properties": {
+					"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4"] }
+				}
+			},
+			"then": {
+				"additionalProperties": false,
+				"properties": {
+					"specVersion": { "enum": ["2.1", "2.2", "2.3", "2.4"] },
+					"kind": {
+						"enum": ["project", null]
+					},
+					"type": {
+						"enum": ["theme-library"]
+					},
+					"metadata": {
+						"$ref": "../project.json#/definitions/metadata"
+					},
+					"framework": {
+						"$ref": "../project.json#/definitions/framework"
+					},
+					"resources": {
+						"$ref": "library.json#/definitions/resources"
+					},
+					"builder": {
+						"$ref": "#/definitions/builder"
+					},
+					"server": {
+						"$ref": "../project.json#/definitions/server"
+					},
+					"customConfiguration": {
+						"type": "object",
+						"additionalProperties": true
+					}
+				}
+			},
+			"else": {
+				"additionalProperties": false,
+				"properties": {
+					"specVersion": { "enum": ["2.0"] },
+					"kind": {
+						"enum": ["project", null]
+					},
+					"type": {
+						"enum": ["theme-library"]
+					},
+					"metadata": {
+						"$ref": "../project.json#/definitions/metadata"
+					},
+					"framework": {
+						"$ref": "../project.json#/definitions/framework"
+					},
+					"resources": {
+						"$ref": "library.json#/definitions/resources"
+					},
+					"builder": {
+						"$ref": "#/definitions/builder"
+					},
+					"server": {
+						"$ref": "../project.json#/definitions/server"
+					}
 				}
 			}
 		}
 	},
-
 	"definitions": {
 		"builder": {
 			"type": "object",
diff --git a/test/lib/specifications/Specification.js b/test/lib/specifications/Specification.js
index 6fbafbe74..aee440410 100644
--- a/test/lib/specifications/Specification.js
+++ b/test/lib/specifications/Specification.js
@@ -149,7 +149,7 @@ test("Migrate legacy project unexpected configuration", async (t) => {
 	const err = await t.throwsAsync(Specification.create(t.context.basicProjectInput));
 
 	t.is(err.message,
-		"project application.a defines unsupported Specification Version 1.0. Please manually upgrade to 2.0 or " +
+		"project application.a defines unsupported Specification Version 1.0. Please manually upgrade to 3.0 or " +
 		"higher. For details see https://sap.github.io/ui5-tooling/pages/Configuration/#specification-versions - " +
 		"An attempted migration to a supported specification version failed, likely due to unrecognized " +
 		"configuration. Check verbose log for details.",
diff --git a/test/lib/validation/schema/__helper__/extension.js b/test/lib/validation/schema/__helper__/extension.js
index 33143db77..79799ee96 100644
--- a/test/lib/validation/schema/__helper__/extension.js
+++ b/test/lib/validation/schema/__helper__/extension.js
@@ -18,7 +18,7 @@ export default {
 
 		customConfiguration.defineTests(test, assertValidation, type, additionalConfiguration);
 
-		["2.6", "2.5", "2.4", "2.3", "2.2", "2.1", "2.0"].forEach((specVersion) => {
+		["3.0", "2.6", "2.5", "2.4", "2.3", "2.2", "2.1", "2.0"].forEach((specVersion) => {
 			test(`kind: extension / type: ${type} basic (${specVersion})`, async (t) => {
 				await assertValidation(t, Object.assign({
 					"specVersion": specVersion,
@@ -66,5 +66,57 @@ export default {
 					}]);
 				});
 		});
+
+		["2.6", "2.5", "2.4", "2.3", "2.2", "2.1", "2.0"].forEach((specVersion) => {
+			test(`kind: extension / type: ${type}: Invalid metadata.name (${specVersion})`, async (t) => {
+				await assertValidation(t, Object.assign({
+					"specVersion": specVersion,
+					"type": type,
+					"metadata": {
+						"name": {}
+					}
+				}, additionalConfiguration), [{
+					dataPath: "/metadata/name",
+					keyword: "type",
+					message: "should be string",
+					params: {
+						type: "string"
+					}
+				}]);
+			});
+		});
+
+		["3.0"].forEach((specVersion) => {
+			test(`kind: extension / type: ${type}: Invalid metadata.name (${specVersion})`, async (t) => {
+				await assertValidation(t, Object.assign({
+					"specVersion": specVersion,
+					"type": type,
+					"metadata": {
+						"name": {}
+					}
+				}, additionalConfiguration), [{
+					dataPath: "/metadata/name",
+					keyword: "type",
+					message: "should be string",
+					params: {
+						type: "string",
+					},
+				}, {
+					dataPath: "/metadata/name",
+					keyword: "errorMessage",
+					message: `Not a valid extension name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+					params: {
+						errors: [{
+							dataPath: "/metadata/name",
+							keyword: "type",
+							message: "should be string",
+							params: {
+								type: "string",
+							}
+						}]
+					},
+				}]);
+			});
+		});
 	}
 };
diff --git a/test/lib/validation/schema/__helper__/project.js b/test/lib/validation/schema/__helper__/project.js
index 777aeba51..50737b761 100644
--- a/test/lib/validation/schema/__helper__/project.js
+++ b/test/lib/validation/schema/__helper__/project.js
@@ -75,25 +75,6 @@ export default {
 				}]);
 			});
 
-			test(`${type} (specVersion ${specVersion}): Invalid metadata.name`, async (t) => {
-				await assertValidation(t, {
-					"specVersion": specVersion,
-					"type": type,
-					"metadata": {
-						"name": {}
-					}
-				}, [
-					{
-						dataPath: "/metadata/name",
-						keyword: "type",
-						message: "should be string",
-						params: {
-							type: "string"
-						}
-					}
-				]);
-			});
-
 			test(`${type} (specVersion ${specVersion}): Invalid metadata.copyright`, async (t) => {
 				await assertValidation(t, {
 					"specVersion": specVersion,
@@ -278,5 +259,54 @@ export default {
 				}]);
 			});
 		});
+
+		["2.6", "2.5", "2.4", "2.3", "2.2", "2.1", "2.0"].forEach((specVersion) => {
+			test(`${type} (specVersion ${specVersion}): Invalid metadata.name`, async (t) => {
+				await assertValidation(t, {
+					"specVersion": specVersion,
+					"type": type,
+					"metadata": {
+						"name": {}
+					}
+				}, [
+					{
+						dataPath: "/metadata/name",
+						keyword: "type",
+						message: "should be string",
+						params: {
+							type: "string"
+						}
+					}
+				]);
+			});
+		});
+
+		["3.0"].forEach((specVersion) => {
+			test(`${type} (specVersion ${specVersion}): Invalid metadata.name`, async (t) => {
+				await assertValidation(t, {
+					"specVersion": specVersion,
+					"type": type,
+					"metadata": {
+						"name": {}
+					}
+				}, [
+					{
+						dataPath: "/metadata/name",
+						keyword: "errorMessage",
+						message: `Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+						params: {
+							errors: [{
+								dataPath: "/metadata/name",
+								keyword: "type",
+								message: "should be string",
+								params: {
+									type: "string",
+								}
+							}]
+						},
+					}
+				]);
+			});
+		});
 	}
 };
diff --git a/test/lib/validation/schema/specVersion/kind/extension.js b/test/lib/validation/schema/specVersion/kind/extension.js
index 565b92245..817e6c31b 100644
--- a/test/lib/validation/schema/specVersion/kind/extension.js
+++ b/test/lib/validation/schema/specVersion/kind/extension.js
@@ -152,3 +152,43 @@ test.after.always((t) => {
 		}]);
 	});
 });
+
+test("Legacy: Special characters in name (task)", async (t) => {
+	await assertValidation(t, {
+		"specVersion": "2.0",
+		"kind": "extension",
+		"type": "task",
+		"metadata": {
+			"name": "ä".repeat(51)
+		},
+		"task": {
+			"path": "task.js"
+		}
+	});
+});
+
+test("Legacy: Special characters in name (server-middleware)", async (t) => {
+	await assertValidation(t, {
+		"specVersion": "2.0",
+		"kind": "extension",
+		"type": "server-middleware",
+		"metadata": {
+			"name": "@my(middleware)"
+		},
+		"middleware": {
+			"path": "middleware.js"
+		}
+	});
+});
+
+test("Legacy: Special characters in name (project-shim)", async (t) => {
+	await assertValidation(t, {
+		"specVersion": "2.0",
+		"kind": "extension",
+		"type": "project-shim",
+		"metadata": {
+			"name": "my/(project)-shim"
+		},
+		"shims": {}
+	});
+});
diff --git a/test/lib/validation/schema/specVersion/kind/extension/project-shim.js b/test/lib/validation/schema/specVersion/kind/extension/project-shim.js
index 3fb2fb286..b2583a12b 100644
--- a/test/lib/validation/schema/specVersion/kind/extension/project-shim.js
+++ b/test/lib/validation/schema/specVersion/kind/extension/project-shim.js
@@ -15,6 +15,11 @@ async function assertValidation(t, config, expectedErrors = undefined) {
 		});
 		validationError.errors.forEach((error) => {
 			delete error.schemaPath;
+			if (error.params && Array.isArray(error.params.errors)) {
+				error.params.errors.forEach(($) => {
+					delete $.schemaPath;
+				});
+			}
 		});
 		t.deepEqual(validationError.errors, expectedErrors);
 	} else {
@@ -122,6 +127,79 @@ test.after.always((t) => {
 	});
 });
 
+["3.0"].forEach(function(specVersion) {
+	test(`Invalid extension name (specVersion ${specVersion})`, async (t) => {
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"kind": "extension",
+			"type": "project-shim",
+			"metadata": {
+				"name": "illegal/name"
+			},
+			"shims": {}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid extension name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "pattern",
+					message: `should match pattern "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$"`,
+					params: {
+						pattern: "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$",
+					}
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"kind": "extension",
+			"type": "project-shim",
+			"metadata": {
+				"name": "a"
+			},
+			"shims": {}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid extension name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "minLength",
+					message: "should NOT be shorter than 3 characters",
+					params: {
+						limit: 3,
+					}
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"kind": "extension",
+			"type": "project-shim",
+			"metadata": {
+				"name": "a".repeat(51)
+			},
+			"shims": {}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid extension name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "maxLength",
+					message: "should NOT be longer than 50 characters",
+					params: {
+						limit: 50,
+					}
+				}]
+			},
+		}]);
+	});
+});
 
 const additionalConfiguration = {
 	"shims": {
diff --git a/test/lib/validation/schema/specVersion/kind/extension/server-middleware.js b/test/lib/validation/schema/specVersion/kind/extension/server-middleware.js
index 6a97ac218..54dab5cbd 100644
--- a/test/lib/validation/schema/specVersion/kind/extension/server-middleware.js
+++ b/test/lib/validation/schema/specVersion/kind/extension/server-middleware.js
@@ -15,6 +15,11 @@ async function assertValidation(t, config, expectedErrors = undefined) {
 		});
 		validationError.errors.forEach((error) => {
 			delete error.schemaPath;
+			if (error.params && Array.isArray(error.params.errors)) {
+				error.params.errors.forEach(($) => {
+					delete $.schemaPath;
+				});
+			}
 		});
 		t.deepEqual(validationError.errors, expectedErrors);
 	} else {
@@ -40,6 +45,86 @@ test.after.always((t) => {
 	t.context.ajvCoverage.verify(thresholds);
 });
 
+["3.0"].forEach(function(specVersion) {
+	test(`Invalid extension name (specVersion ${specVersion})`, async (t) => {
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"kind": "extension",
+			"type": "server-middleware",
+			"metadata": {
+				"name": "illegal-🦜"
+			},
+			"middleware": {
+				"path": "/bar"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid extension name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "pattern",
+					message: `should match pattern "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$"`,
+					params: {
+						pattern: "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$",
+					}
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"kind": "extension",
+			"type": "server-middleware",
+			"metadata": {
+				"name": "a"
+			},
+			"middleware": {
+				"path": "/bar"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid extension name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "minLength",
+					message: "should NOT be shorter than 3 characters",
+					params: {
+						limit: 3,
+					}
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"kind": "extension",
+			"type": "server-middleware",
+			"metadata": {
+				"name": "a".repeat(51)
+			},
+			"middleware": {
+				"path": "/bar"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid extension name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "maxLength",
+					message: "should NOT be longer than 50 characters",
+					params: {
+						limit: 50,
+					}
+				}]
+			},
+		}]);
+	});
+});
+
 const additionalConfiguration = {
 	"middleware": {
 		"path": "/foo"
diff --git a/test/lib/validation/schema/specVersion/kind/extension/task.js b/test/lib/validation/schema/specVersion/kind/extension/task.js
index 7abbf36d0..63f5be3e9 100644
--- a/test/lib/validation/schema/specVersion/kind/extension/task.js
+++ b/test/lib/validation/schema/specVersion/kind/extension/task.js
@@ -15,6 +15,11 @@ async function assertValidation(t, config, expectedErrors = undefined) {
 		});
 		validationError.errors.forEach((error) => {
 			delete error.schemaPath;
+			if (error.params && Array.isArray(error.params.errors)) {
+				error.params.errors.forEach(($) => {
+					delete $.schemaPath;
+				});
+			}
 		});
 		t.deepEqual(validationError.errors, expectedErrors);
 	} else {
@@ -40,6 +45,86 @@ test.after.always((t) => {
 	t.context.ajvCoverage.verify(thresholds);
 });
 
+["3.0"].forEach(function(specVersion) {
+	test(`Invalid extension name (specVersion ${specVersion})`, async (t) => {
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"kind": "extension",
+			"type": "task",
+			"metadata": {
+				"name": "illegal-🦜"
+			},
+			"task": {
+				"path": "/bar"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid extension name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "pattern",
+					message: `should match pattern "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$"`,
+					params: {
+						pattern: "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$",
+					}
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"kind": "extension",
+			"type": "task",
+			"metadata": {
+				"name": "a"
+			},
+			"task": {
+				"path": "/bar"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid extension name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "minLength",
+					message: "should NOT be shorter than 3 characters",
+					params: {
+						limit: 3,
+					}
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"kind": "extension",
+			"type": "task",
+			"metadata": {
+				"name": "a".repeat(51)
+			},
+			"task": {
+				"path": "/bar"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid extension name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "maxLength",
+					message: "should NOT be longer than 50 characters",
+					params: {
+						limit: 50,
+					}
+				}]
+			},
+		}]);
+	});
+});
+
 const additionalConfiguration = {
 	"task": {
 		"path": "/foo"
diff --git a/test/lib/validation/schema/specVersion/kind/project.js b/test/lib/validation/schema/specVersion/kind/project.js
index 231c0ef29..2c9c2290a 100644
--- a/test/lib/validation/schema/specVersion/kind/project.js
+++ b/test/lib/validation/schema/specVersion/kind/project.js
@@ -195,3 +195,43 @@ test("No specVersion", async (t) => {
 		}
 	}]);
 });
+
+test("Legacy: Special characters in name (application)", async (t) => {
+	await assertValidation(t, {
+		"specVersion": "2.0",
+		"type": "application",
+		"metadata": {
+			"name": "/".repeat(51)
+		}
+	});
+});
+
+test("Legacy: Special characters in name (library)", async (t) => {
+	await assertValidation(t, {
+		"specVersion": "2.0",
+		"type": "library",
+		"metadata": {
+			"name": "my/(library)"
+		}
+	});
+});
+
+test("Legacy: Special characters in name (theme-library)", async (t) => {
+	await assertValidation(t, {
+		"specVersion": "2.0",
+		"type": "theme-library",
+		"metadata": {
+			"name": "my/(theme)-library"
+		}
+	});
+});
+
+test("Legacy: Special characters in name (module)", async (t) => {
+	await assertValidation(t, {
+		"specVersion": "2.0",
+		"type": "module",
+		"metadata": {
+			"name": "my/(module)"
+		}
+	});
+});
diff --git a/test/lib/validation/schema/specVersion/kind/project/application.js b/test/lib/validation/schema/specVersion/kind/project/application.js
index 81b959e4f..4c0a73d5f 100644
--- a/test/lib/validation/schema/specVersion/kind/project/application.js
+++ b/test/lib/validation/schema/specVersion/kind/project/application.js
@@ -942,4 +942,72 @@ test.after.always((t) => {
 	});
 });
 
+["3.0"].forEach(function(specVersion) {
+	test(`Invalid project name (specVersion ${specVersion})`, async (t) => {
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"type": "application",
+			"metadata": {
+				"name": "illegal/name"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "pattern",
+					message: `should match pattern "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$"`,
+					params: {
+						pattern: "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$",
+					},
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"type": "application",
+			"metadata": {
+				"name": "a"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "minLength",
+					message: "should NOT be shorter than 3 characters",
+					params: {
+						limit: 3,
+					},
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"type": "application",
+			"metadata": {
+				"name": "a".repeat(51)
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "maxLength",
+					message: "should NOT be longer than 50 characters",
+					params: {
+						limit: 50,
+					},
+				}]
+			},
+		}]);
+	});
+});
+
 project.defineTests(test, assertValidation, "application");
diff --git a/test/lib/validation/schema/specVersion/kind/project/library.js b/test/lib/validation/schema/specVersion/kind/project/library.js
index 3ba3ecfd6..60e0c6225 100644
--- a/test/lib/validation/schema/specVersion/kind/project/library.js
+++ b/test/lib/validation/schema/specVersion/kind/project/library.js
@@ -1115,4 +1115,71 @@ test.after.always((t) => {
 	});
 });
 
+["3.0"].forEach(function(specVersion) {
+	test(`Invalid project name (specVersion ${specVersion})`, async (t) => {
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"type": "library",
+			"metadata": {
+				"name": "illegal-🦜"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "pattern",
+					message: `should match pattern "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$"`,
+					params: {
+						pattern: "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$",
+					},
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"type": "library",
+			"metadata": {
+				"name": "a"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "minLength",
+					message: "should NOT be shorter than 3 characters",
+					params: {
+						limit: 3,
+					},
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"type": "library",
+			"metadata": {
+				"name": "a".repeat(51)
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "maxLength",
+					message: "should NOT be longer than 50 characters",
+					params: {
+						limit: 50,
+					},
+				}]
+			},
+		}]);
+	});
+});
 project.defineTests(test, assertValidation, "library");
diff --git a/test/lib/validation/schema/specVersion/kind/project/module.js b/test/lib/validation/schema/specVersion/kind/project/module.js
index a750806b4..06e059cf7 100644
--- a/test/lib/validation/schema/specVersion/kind/project/module.js
+++ b/test/lib/validation/schema/specVersion/kind/project/module.js
@@ -15,6 +15,11 @@ async function assertValidation(t, config, expectedErrors = undefined) {
 		});
 		validationError.errors.forEach((error) => {
 			delete error.schemaPath;
+			if (error.params && Array.isArray(error.params.errors)) {
+				error.params.errors.forEach(($) => {
+					delete $.schemaPath;
+				});
+			}
 		});
 		t.deepEqual(validationError.errors, expectedErrors);
 	} else {
@@ -344,4 +349,72 @@ test.after.always((t) => {
 	});
 });
 
+["3.0"].forEach(function(specVersion) {
+	test(`Invalid project name (specVersion ${specVersion})`, async (t) => {
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"type": "module",
+			"metadata": {
+				"name": "illegal-🦜"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "pattern",
+					message: `should match pattern "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$"`,
+					params: {
+						pattern: "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$",
+					}
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"type": "module",
+			"metadata": {
+				"name": "a"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "minLength",
+					message: "should NOT be shorter than 3 characters",
+					params: {
+						limit: 3,
+					},
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"type": "module",
+			"metadata": {
+				"name": "a".repeat(51)
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "maxLength",
+					message: "should NOT be longer than 50 characters",
+					params: {
+						limit: 50,
+					},
+				}]
+			},
+		}]);
+	});
+});
+
 project.defineTests(test, assertValidation, "module");
diff --git a/test/lib/validation/schema/specVersion/kind/project/theme-library.js b/test/lib/validation/schema/specVersion/kind/project/theme-library.js
index 24abd992c..220f193fa 100644
--- a/test/lib/validation/schema/specVersion/kind/project/theme-library.js
+++ b/test/lib/validation/schema/specVersion/kind/project/theme-library.js
@@ -348,4 +348,71 @@ test.after.always((t) => {
 	});
 });
 
+["3.0"].forEach(function(specVersion) {
+	test(`Invalid project name (specVersion ${specVersion})`, async (t) => {
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"type": "theme-library",
+			"metadata": {
+				"name": "illegal-🦜"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "pattern",
+					message: `should match pattern "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$"`,
+					params: {
+						pattern: "^(?:@[0-9a-z-_.]+\\/)?[a-z][0-9a-z-_.]*$",
+					},
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"type": "theme-library",
+			"metadata": {
+				"name": "a"
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "minLength",
+					message: "should NOT be shorter than 3 characters",
+					params: {
+						limit: 3,
+					},
+				}]
+			},
+		}]);
+		await assertValidation(t, {
+			"specVersion": specVersion,
+			"type": "theme-library",
+			"metadata": {
+				"name": "a".repeat(51)
+			}
+		}, [{
+			dataPath: "/metadata/name",
+			keyword: "errorMessage",
+			message: `Not a valid project name. It must consist of lowercase alphanumeric characters, dash, underscore and period only. Additionally, it may contain an npm-style package scope. For details see: https://sap.github.io/ui5-tooling/stable/pages/Configuration/#name`,
+			params: {
+				errors: [{
+					dataPath: "/metadata/name",
+					keyword: "maxLength",
+					message: "should NOT be longer than 50 characters",
+					params: {
+						limit: 50,
+					},
+				}]
+			},
+		}]);
+	});
+});
 project.defineTests(test, assertValidation, "theme-library");