Shared parameters are available for both single- and multi-category tags.
Click File tabNew (Annotation Symbol), select a template (such as, Door Tag.rft) and click Open.
The Family Editor opens.
The selected parameter displays in the Category Parameters list.
When you tag instances of the category in the project, the tag label displays a value only if those category instances have the external parameter. For example, you create a door tag with the shared parameter Door Trim Finish. You can then tag all doors with that tag, but the tag displays a value for Door Trim Finish only if the door has that shared parameter, otherwise a “?” appears in the tag.