The file Package.def is part of every package. It defines the position of the package in the PackageGroup.

A typical example (excerpt from the MeVisLab/Standard/Package.def):

Package {
  packageGroup = MeVisLab
  packageName  = Standard

  owner        = "MeVis Medical Solutions"
  description  = "Standard MeVisLab Modules"
}

	Note
	In principle, the package structure is defined by Package.def. However, the implementation of the package handling expects that all packages are below their PackageGroup.