Glossary/Plant3D
UDA (User-Defined Attribute)
A custom property Plant3D lets a project define for an asset class, beyond the built-in fields.
A UDA (user-defined attribute) is a custom property a Plant3D project adds to an asset class — a vendor name, a spec code, a manufacturer field — on top of Plant3D's built-in properties. UDA values are stored in the project database, not on the drawing entity itself, which is why reading or writing them requires that database to be set, not just the DWG file.
This is distinct from a block attribute, which lives entirely on the drawing entity and needs no separate database.
P3DSync