This attribute allows the mirroring of an item after its insertion in the environment.
With True value, the item can be mirrored after its insertion in the environment, through the Mirror option, by right clicking.
In the registration of this attribute, its default setting defines that it is automatically created (in a hidden way) for all entities (property Automatic Creation) with default value False, that is, the attribute is applied in all modules to define that the modules, originally, cannot be mirrored. If you need to define that the item can be mirrored in the environment, you need to apply the attribute in the module and change its value to True.
Doors on counters and cabinets, to reverse the opening direction after insertion into the environment.
Using the images below, you can see that on the left with the CanMirror attribute with value False or not applied (due to its default value - False) on the port, the Mirror option is not displayed among the options displayed when right-clicking on the port. On the right, with the CanMirror attribute with value True applied to the port, the Mirror option is displayed when right-clicked on the port.
To apply the attribute, click here and see how to proceed.