The phrase "doing business as" (abbreviated DBA or d/b/a) is a legal term, meaning that the name of the business or operation does not include the legal name of its proprietor, the names of all partners, or the official registered name of the limited partnership or corporation that owns it.
Definition from en.wikipedia.org/wiki/Doing_business_as

(Trademark, service mark or dba) - If a trademark, service mark, or dba is to be used it must first be filed with and approved by the commissioner. After the certificate of authority is issued, the name approved by the commissioner must be used by the HMO on all advertising and forms distributed to the public. Definition from www.tdi.state.tx.us/company/hmo/defintns.html