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 identification number of an object. Use with all content types.
Note that object IDs are temporary, and may change when you reopen a model, or use the read in command in Tekla Model Sharing, for example.