39 CFR 501.20 - Discontinued Postage Evidencing Indicia.
(a)Decertified indicia (evidence of pre-paid postage) are indicia that have been withdrawn by the Postal Service as valid forms of postage evidence through publication by the Postal Service in the Federal Register, or by voluntary withdrawal undertaken by the provider.
(b) Effective January 1, 2016, all Postage Evidencing Systems (postage meters and PC Postage products) will be required to produce Information-Based Indicia (IBI) or Intelligent Mail Indicia (IMI) for evidence of pre-paid postage. Non-IBI and non-IMI indicia will be decertified effective January 1, 2016, and may not be used as a valid form of postage evidence. These decertified indicia will not be recognized as valid postage after December 31, 2015.