Only one constraint can be defined per Change Object and a relationship link. For example if a constraint is defined for a Problem Report base type and wt.change2.ReportedAgainst link then another constraint for the Problem Report base type and a subtype of wt.change2.ReportedAgainst link cannot be created. However, another constraint can be defined for a Problem Report subtype and wt.change2.ReportedAgainst or subtype link even though a constraint has already been defined for the Problem Report base type.

It is very easy to define constraints which may severely limit the ability of users to be flexible in their associations to changes. Before establishing new constraints on the links, careful examination of the roles of the users in the change process should be conducted and the rules should be as “open” as possible (as opposed to as “constrained” as possible).