Warning message stating a component has already been designated/undesignated in Cabling

[ClintWalton]

When designating components in the cabling application, if a component is selected that was already designated, no feedback is given letting the user know this.  There should be a prompt saying, "This component is already designated.  Do you wish to undesignate it?"  The same is also true for undesignating.

[JimBarrettSmith]

In Creo 2.0 if a component is already designated it cannot be selected during the designation command.

Likewise when undesignating a component Cabling design will only allow you to select designated components. 

You can also turn on the ref des labels to visually identify which components are designated.

Thus you based on selection or label you know whether a component is designated