http://www.rfc-editor.org/rfc/rfc2580.txt
RFC 2580: Conformance Statements for SMIv2, K. McCloghrie, D. Perkins, J. Schoenwaelder1999-04-01T23:00:00-00:00Collections of related objects are defined in MIB modules. It may be useful to define the acceptable lower-bounds of implementation, along with the actual level of implementation achieved. It is the purpose of this document to define the notation used for these purposes. [STANDARDS-TRACK]