missing column in songbird output

[bck243]

Hello!

I ran songbird on my marine dataset and it seemed to have worked well for most variables. However, for the categorical variable, water mass, there are only output differential columns for some of the options. The dataset contains taxa and metadata corresponding to the following closest end member water masses: "LCDW" "Upper" "UCDW" "AAIW" "AABW" "NPIW" . But, the differential file only has columns entitled: "closest_end_member.T.AAIW."
"closest_end_member.T.LCDW." "closest_end_member.T.NPIW." "closest_end_member.T.UCDW."
"closest_end_member.T.Upper.", so "AABW" is missing. I understand that if you input a boolean variable, there will only be a column for True, and taxa negatively associated with that column would be associated with "False", but I'm not sure how to interpret all but one of 6 categories being present. If this is by design, ow would I find taxa associated with AABW?

Thanks!
Bethany