Some TC properties refer to elements in the model, for example "Sources" and "Top capsule". By default such a reference consists of a URI that identifies the model file where the element is located (relative to the Eclipse workspace folder), and the unique ID of the element. Here is an example:
tc.sources = [
'platform:/resource/xxx/CPPModel.emx#_KZK5YBuoEeyDNsbmUkqd7g'
];
You can navigate to the referenced element in the Project Explorer by Ctrl-clicking on the URI (which then becomes a hyperlink). You can also hover the mouse over the URI to get a popup showing the element name.
There are two workspace preferences (in RealTime Development - Transformation Configuration Editor - Model References) you can set to change the format of these URIs:
Use relative URIs to reference model elements
If set, the file part of the URI will be relative to the TC file rather than the workspace folder.
Use fully qualified names in model element URI references (instead of xmi id)
If set, the element's fully qualified name will be used instead of its unique ID.
Both these preferences make model element URI references more portable so you can copy/paste a TC file (or a project containing a TC file) without having to manually update all model element references in the copied TC. However, certain refactorings (like moving a referenced element) may then require you to update the URIs. Note that the preferences only affect what URI format to use for newly created model element references, and will not change existing references in the TC.
The navigation and mouse hover features mentioned above works regardless of how these preferences are set (but the need for these features may be smaller since with qualified names it's easier to conclude directly from the URI what element it references).