Path variables specify locations on the file system. The location of linked resources may be specified relative to these path variables. They allow you to avoid references to a fixed location on your file system.
By using a path variable, you can share projects containing linked resources with team members without requiring the exact same directory structure as on your file system.
You can load a project that uses path variables even if you do not currently have all the path variables defined in your workspace. A linked resource that uses a missing path variable is flagged using a special decorator icon. In addition, the File > Properties > Info property page and the Properties view ( Window > Show View > Other... > General > Properties) for a linked resource indicate the variable and whether it is defined or not. A path variable can also specify a location that does not currently exist on the file system. Linked resources that use such a path variable are indicated using the same decorator icon mentioned above.
You can create new path variables and edit and remove existing path variables on the General > Workspace > Linked Resources preference page.
Creating linked resources
Viewing resource properties