Can the Inspector Annotations only link to an RTF file?

As an alternative, I tried converting the auto-made RTF to Markdown, but of course that failed since doing so just made a new file.

But I don’t mind a workaround like that. Is there some way I can attach a non-RTF file so that it appears as another file’s Inspector Attachment? Or for that matter, how can I attach any file to be the Annotations file linked to another file? Or can this only be done by typing inside the Annotations field and letting DevonThink create an RTF?

See Annotations popup in Annotations & Reminder inspector, there are templates for rich text and Markdown annotations.

Holy crap! My glasses were actually on top of my head the whole time. Thanks!