Sounds like those attributes are being created in GDL objects saved in your library.
When you look at the Attribute Manager are those attributes shown in italic text?
If so they are being generated for GDL objects.
Usually 3rd party objects like Cadimage do this.
You will have to delete the objects (I don't know any way to find them specifically - just trial and error) or live with those attributes.
Barry.
One of the forum moderators.
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