System Tables - Create Location

All the system tables I've been creating I've added in the audit columns as specified in the System Tables doc as follows: 

created_by varchar(8) null,

create_dt datetime null,

create_loc varchar(16) null,

last_updated_by varchar(8) null,

last_update_dt datetime null

and after running UP_POPULATE_REFTABLES_TABLE and UP_POPULATE_REFERENCE_METADATA, they all work properly except for create_loc. I've looked in TR_REFERENCE_COLUMN, and those columns look the same as the ones that were system created, so I'm not sure what I'm missing. 
Has anyone else seen this happen? Any idea what I should be doing differently?
thanks
Brian