has part numeral textual entity telephone number http://en.wikipedia.org/wiki/Telephone_number A telephone number is a textual entity consisting of a sequence of digits used to call from one telephone line to another in a public switched telephone network. MB: This class should probably be a subclass to CRID. However, the textual definition of CRID right now states that each instance has the CRID identifier as a part. This is not the case for telephone numbers. Therefore, they cannot be subsumed under CRID now. I am looking into changing IAO accordingly. Once that is done, the class ought to be a subclass of CRID. Mathias Brochhausen