Release 10.1A: OpenEdge Development:
ADM Reference

UpdatableColumns

A comma separated list of the updatable columns for this SmartDataObject (SDO), or a list of all updatable columns of contained data objects qualified by their object names.

Data type: CHARACTER

Notes:

Read only.
If you want a list of updatable columns in different tables delimited by CHR(1), instead of by a comma, that identifies which columns are from which table in the event of a join, use the UpdatableColumnsByTable property.