I'm trying to auto-fill the "Reference #" field on the Library tab.
I store this data in the "Comment" field of the FLAC tag.

I know you stated:
OrangeCD only reads all attributes that have corresponding fields in OrangeCD database. Everything else, including any custom tags, is ignored.
...which means that since OCD has no "Comment" field, it will ignore the "Comment" field in the FLAC tag, correct?
So, the question(s) is (are):
Which field in the FLAC tag corresponds with the "Reference #" field on the Library tab? (I tried "Catalog #" but that didn't work)
OR
Should I store the data in a field that OCD recognizes (but which one?) and then use the Tools/Advanced/Transfer Function to move the data to the "Reference #" field?

Any chance for future support of the "Comment" or "Catalog #" fields in the FLAC tag? ;D
Also, a side note: OCD still isn't reading the "Year" field in the FLAC tag at all. :-[