In OpenEdge Releases prior to 10.1A, ABL allowed large object (BLOB and CLOB) operations in subtransactions. However, if the user undid the subtransaction they got the following message:

Undo of sub-transaction modifying a large object.  Backing out transaction. 
(11599)

This message told the user that not just the subtransaction, but the entire transaction was rolled back.

Starting with Release 10.1A, subtransactions containing changes to large object (LOB) fields can be undone without undoing the entire transaction. Users no longer get the previous message and, more importantly, the subtransaction containing the LOB operation is rolled back like any other subtransaction. This feature applies only to LOB operations in the OpenEdge database. The restrictions on LOB operations in subtransactions still applies to the Oracle DataServer.

Note that this feature does not apply to temporary tables. Temp-tables must be NO-UNDO if they contain binary (BLOB) or character large object (CLOB) fields.