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.

Shows the values entered in the Connection code box on the End conditions tab in the user-defined attributes dialog box of the part. CONN_CODE_END1 shows the value in the Start box and CONN_CODE_END2 in the End box.