When ODMAD is working with target domain objects, it's populating a "stamping" attribute (adminDescription by default), which indicates how ODMAD worked with them.
When ODMAD is creating a new target object, it's populated by "Created by Dirsync". Which means that target domain object did not exist and ODMAD workflow has created it
When target object was created manually or by any means, other than ODMAD, but workflow Match has found it as a matched object, it'll populate adminDescription with "Matched by Dirsync" content.
Those values can be seen in the workflow changelog, created by Stage module.
And depending on how object was created or matched, subsequent updates can be configured in the template:
