What is the "CT" title format element supposed to display?

For LMS 7.7.3 - 1375965195, on the Settings, Interface tab there is a place to set the Title format.

I put this string in today:

TRACKNUM. TITLE from ALBUM by ARTIST (YEAR, GENRE, CT, BITRATE)

and everything is fine (well, not BITRATE; for FLACs on 7.8.0. it displays something like ###kbps VBR and on 7.7.3 it displays ###### where # is a numeric digit) except for CT (listed as "content type" in the informational hover text) which just displays "CT" instead of whatever content type is supposed to be.

Not a big deal, just wondered if it's supposed to work.