IETF MANET Working Group A. Baryun Internet-Draft July 30, 2012 Expires: January 31, 2013 Intended status: Best Current Practice Intended to update RFC2119 Key Words of Conditional Language of Requirements Levels draft-baryun-rfc2119-update-00.txt Abstract In many standards track documents conditional words are used to signify the requirements in the specification. These words are prefered to be capitalized. This document defines these conditional words as they should be interpreted in IETF documents. Authors who follow these guidelines should incorporate this phrase near the beginning of their document. The additional key words to words described in RFC2119 are; "IF, THEN", "ELSE IF", "ELSE". Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on January 31, 2013. Copyright Notice Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved. Baryun Expires January 31, 2013 [Page 1] Internet-Draft Conditional Requirement July 2012 This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. 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Introduction Many IETF RFCs have specified conditional language without significant requirement level as used in the RFC2119 key words. This document describe key words that will help and facilitate to the readers, users and designers in understanding conditions, and consequences of conditions of specifications. 2. The Conditional Key words Note that the force of these words is modified by the requirement level of the document in which they are used. IF x THEN y: the possibility that the condition of x occur, but when it does the function y MUST occur. ELSE IF v THEN w: the condition v is tested only when x does not occur, but when v occurs, the function w MUST occur. ELSE z: the function(s) MUST occur only when all the conditions above, e.g. as x and v conditions do not occur Baryun Expires January 31, 2013 [Page 2] Internet-Draft Conditional Requirement July 2012 IF NOT x THEN y: the possibility that the condition of x MUST NOT occur, but when it does not occur the function y MUST occur. 3. Guidance in the use of these Imperatives (TBD) Imperatives of the type defined in this document must be used with care and sparingly. In particular, they MUST only be used where it is actually required for specifying conditional behavior which has interoperability potential. For incetance, they must not be used to try to impose a particular conditional method on implementors where the method is not required for interoperability. 4. Security Considerations (TBD) These additional conditional terms are frequently used to specify conditional behavior with security implications. The effects on security of not implementing as "IF, THEN", "ELSE" or "ELSE IF", or doing something the specification says MUST do under conditions may be very subtle. I-D or RFC Document author(s) should take the time to elaborate the security implications of not following conditional requirements as most implementors will not have had the benefit of the experience and discussion that produced the specification. 5. Acknowledgments (TBD) 6. References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. Author's Address Abdussalam Nuri Baryun Email: abdussalambaryun@gmail.com Baryun Expires January 31, 2013 [Page 3]