14 CFR 215.3: Use of name.

In holding out to the public and in performing air transportation services, a direct air carrier or foreign direct air carrier subject to this part shall use only the name in which its operating authorization is issued or trade name is registered, and shall not operate or hold out to the public in a name not acknowledged by the Department to be so registered. Minor variations in the use of this name, including abbreviations, contractions, initial letters, or other variations of the name that are identifiable with the authorized name, are permitted. Slogans and service marks shall not be considered names for the purpose of this part, and their use is not restricted.