This is the CodeSystem that contains all the codes in DDCC Designation Types for Folder (http://smart.who.int/ddcc/CodeSystem/DDCCFolderDesignationTypeCodesystem) and DDCC Designation Types for Folder (http://smart.who.int/ddcc/CodeSystem/DDCCFolderDesignationTypeCodesystem). E.g. what you have to deal with if you get resources containing codes in either of them