Annex SL (which is now Annex-L) is a document of the ISO Technical Management Boards (TMB) Joint Technical Coordination Group (JTCG). The TMB is charged with managing the technical processes associated with implementing new technical standards. This includes the rules which govern standards creation, checking how the process is working, and managing the technical committees which construct the standards. The JTCG reports to the TMB and specifically manages the activities associated with creating and implementing an MSS.
One of its main tasks is to ensure that the input from the various technical committees associated with each standard are represented in the resulting MSS of a given area (i.e. environmental, aerospace, etc.)