[itsme]

The same happened in the German translation. Whereas it is "benutzerdefinierte Gruppe" (Custom Group) in most cases, the settings screen refers to it as "benutzerdefinierte Kategorie" (Custom Category). I'll send you an e-mail, hopefully by Sunday, with the exact German wording.
And I came across another inconsistency regarding "type" / "source" / "source type".
The point is that some terms show up several times: in the tab header of the library, as a field text in the song editor, on the settings screen, in the "configure fields" window, in error messages and there might even be more places. It's confusing for the user if the wording is not exactly identical