This is a template attribute. Template attributes can be used in filtering, or to retrieve data from the model to use in drawings and reports. For example, when you create a report, Tekla Structures replaces the attributes added in the report template with the corresponding object property values.

This attribute shows the value entered in the Checked by box in the part or assembly user-defined attributes. Also shows the value that you have entered in the Checked by box in the Revision handling dialog.