In goswid I put in relationships for compiler and general dependencies. for the command line part it would look something like this:
--parent tag0
--requires tag1,tag2,tag3 // would create a link between tag0 and tag[1-3] with the link type 'requires'.
--compiler tag4 // would create a link between tag0 and tag4 with link type 'compiler' (not in CoSWID spec).
tag5 tag6 tagn // would just put tag5,tag6,tagn into the uSWID file without creating link