Technically, the column is a "registered rowid". There is no requirement that it be
named "objectid", but Desktop doesn't make it easy to name it something else
from the user interface.
The COV# and COV-ID columns were artifacts of how ArcInfo coverage topology
worked. They are not necessary in shapefile, personal geodatabase, file geodatabase,
or ArcSDE tables, nor are FNODE#/TNODE#/LPOLY#/RPOLY#.
- V