The do.ashx?cmd=objsnav command has a options URL parameter that specified the options (as a comma-separated list) to use in the XML generation. For example:

  ../do.ashx?cmd=objsnav&ids=5876&options=none

outputs the XML of the objects with id 5876 without any extra information, whereas:

  ../do.ashx?cmd=objsnav&ids=5876&options=sources,dests

outputs the XML of the same object listing all its sources (objects that have been copied to it) and destinations (objects it has been copied to).