Sec. 21.5  Formal and informal applications.

    (a) Except for an authorization under any of the proviso clauses of 
section 308(a) of the Communications Act of 1934 (47 U.S.C. 308(a)), the 
Commission shall grant the following authorizations only upon written 
application: Station licenses; modifications of station licenses; 
renewals of station licenses; extensions of time to construct; transfers 
and assignments of station licenses or of any rights thereunder.
    (b) Except as may be otherwise permitted by this part, a separate 
written application shall be filed for each instrument of authorization 
requested. Applications may be:
    (1) ``Formal applications'' where the Commission has prescribed in 
this part a standard form; or
    (2) ``Informal applications'' (normally in letter form) where the 
Commission has not prescribed a standard form.
    (c) An informal application will be accepted for filing only if:
    (1) A standard form is not prescribed or clearly applicable to the 
authorization requested;
    (2) It is a document submitted, in duplicate, with a caption which 
indicates clearly the nature of the request, radio service involved, 
location of the station, and the application file number (if known); and
    (3) It contains all the technical details and informational showings 
required by the rules and states clearly and completely the facts 
involved and authorization desired.
[ 44 FR 60534 , Oct. 19, 1979, as amended at  52 FR 37777 , Oct. 9, 1987]