47 C.F.R. § 1.10008 What are IBFS file numbers?
Title 47 - Telecommunication
(a) We assign file numbers to electronic applications in order to facilitate processing. (b) We only assign file numbers for administrative convenience; they do not mean that an application is acceptable for filing. (c) For a description of file number information, see The International Bureau Filing System File Number Format Public Notice, DA–04–568 (released February 27, 2004).
Title 47: Telecommunication
PART 1—PRACTICE AND PROCEDURE
Subpart Y—International Bureau Filing System
§ 1.10008 What are IBFS file numbers?

