The NISPOM (DoD 5220.22-M) establishes the standard procedures and requirements for all government contractors, with regards to classified information. NISPOM is sometimes cited as a standard for sanitization to counter data remanence. The NISPOM actually covers the entire field of government-industrial security, of which data sanitization is a very small part (about two paragraphs in a 141 page document). Furthermore, the NISPOM does not actually specify any particular method. Standards for sanitization are left up to the Cognizant Security Authority. The Defense Security Service provides a Clearing and Sanitization Matrix (C&SM) which does specify methods. As of the June 2007 edition of the DSS C&SM, overwriting is no longer acceptable for sanitization of magnetic media; only degaussing or physical destruction is acceptable.