Handling of Constraints Constraints are prefixed with AASd- followed by a three-digit number. The "d" in "AASd-" was motivated by "in Detail". The numbering of constraints is unique within namespace AASd; a number of a constraint that was removed will not be used again. Note: in the Annex listing the metamodel changes, constraints with prefix AASs- or AASc- are also listed. These are security or data specification constraints, and are now part of the split document parts.