The rules in this subpart D of part 4000 tell you how to compute time periods under our regulations (e.g., for filings with us and issuances to third parties) where the particular regulation calls for their application. (There are specific exceptions or modifications to these rules in § 4007.6 of this chapter (premium payments), and § 4062.10 of this chapter (employer liability payments). In some cases, the PBGC regulations tell you to comply with requirements that are found somewhere other than in the PBGC's own regulations (e.g., requirements under the Internal Revenue Code (Title 26, USC)). In meeting those requirements, you should follow any applicable computation-of-time rules under those other requirements. (Subpart A tells you what filing methods you may use for filings with us. Subpart B tells you what methods you may use to issue a notice or otherwise provide information to any person other than us. Subpart C tells you how we determine your filing or issuance date. Subpart E tells you how to maintain required records in electronic form.)