Archived models store all constraint names without making a difference between user defined and calculated constraints. These models are used with the modify database feature.
You can archive a PDM with the .apm file extension, using the following methods:
Save a PDM as an archived model
Automatically archive PDM after database creation
Select File > Save As, select Archived PDM (bin) or Archived PDM (xml) in the Save As Type list, and click Save.
or
Select Database > Generate Database, click the Options tab, select the Automatic Archive check box in the After Generation groupbox, and click OK.