It should be definable on TermCollection-level, what attributes are available in the TermPortal.

This refers to all attributes available in the TermCollection - default TBX attributes and those that exist due to imported TBX files.

Proprietary attributes added via an import will always be available by default at first.

If an attribute is deactivated, that already has assigned values, those values will be deleted. A warning message will be shown, if such attributes are deactivated.