| Name | Description |
|---|---|
| Comments | Specific comments about the mullions. |
| Length | Maximum length of the mullion. For example, on a mitered mullion, the value is the pre-cut length. This is a read-only value. |
| Mark | Sets a label for the mullions. This value must be unique for each mullion in a project. Revit warns you if the number is already used but allows you to continue using it. (You can see the warning using the Review Warnings tool. See Reviewing Warning Messages.) |