SR 5th ed. How do I create a new Source ID category?

[Mathias]

Simply creating the source is easy, and happens the same way as in 5e - in the editor, in the sources list on your item (which is near the bottom of any editor tab), just create a new source. The question here was how to create a header that groups several of these user-created sources into a collapsible header. This question and answer actually apply to all the games, so the same in 5e as in SR5.