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OPS Area NETMOD Working Group This document presents YANG module file name convention. The convention extends the current YANG module file name using revision‑date, with the YANG semantic version extension. The YANG semantic version extension allows for an informative version to be associated with a particular YANG module revision. This documents updates RFCs 6020, 7950, and draft-ietf-netmod-rfc8407bis.

Introduction This document defines the YANG module file convention. It extends the current convention defined in , , and , which uses revision-date, with the YANG semantic version extension defined in .

Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here.

Motivation The motivation for using YANG semantic version instead of revision date is that it conveys additional information to the user. A revision date only tells the user that it has been updated, while, for instance, a YANG Semver version can tell the user about the module's compatibility level at a glance. Having this information available as early as possible, i.e. in the module file name, makes it possible to quickly identify the module revision; compared to searching in the file contents and checking the revisions. Having the YANG semantic version visible in the file name will make it easier to handle large sets of YANG modules.

Module file names This section updates , , and . If a revision has an associated YANG semantic version (ysv:version) then it MAY use the YANG semantic version instead of the revision date in the file name of a YANG file, where it takes the form: E.g., acme-router-module@2024-05-15.yang or acme‑router‑module#2.0.3.yang. In short, the YANG semantic version file name scheme is recommended in order to simplify for module consumers, i.e. to convey compatibility status at a glance without needing to read the module. YANG module (or submodule) files MAY be identified using either revision-date or YANG semantic version (ysv:version). If the YANG module (or submodule) has an associated YANG semantic version (ysv:version), then a file name that use the YANG semantic version MUST be used. In addition, a file with the revision date in the file name MAY be created as well.

Coexistence with YANG Semver As can be seen above, all valid identifiers for YANG semantic version are valid in the filename as well. The following example is a valid YANG module file name One consequence of this is that there might exist two child modules of version 2.0.0 with the same X.Y.Z digits (2.0.1) but different version labels:

Known incompatibilities There are currently no known publicly available tools that support the YANG semantic version file name schema. There are known proprietary tooling that already uses the file name schema presented in this document. At the IETF 119 Hackathon, there was a project that investigated the feasibility to modify popular YANG tooling to support the proposed schema. There was a successful attempt to modify pyang to support the file name schema and also "recommended-min" previously included in . Furthermore, there were efforts in researching yanger and libyang to support the schema, but the hackathon ended before these projects could be concluded.

IANA Considerations The "YANG Module Names" Registry need to support YANG modules with both the existing file name convention and the file name convention defined in this document. The registry MUST create a file with a YANG semantic version if the YANG module (or submodule) has an associated YANG semantic version (ysv:version). The registry MUST also create a file with the YANG module using a file name with the revision date. It MUST be ensured that the files' contents are identical.

Security Considerations There are no security considerations for this draft.

References Normative References In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONF notifications. [STANDARDS-TRACK] YANG is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols. This document describes the syntax and semantics of version 1.1 of the YANG language. YANG version 1.1 is a maintenance release of the YANG language, addressing ambiguities and defects in the original specification. There are a small number of backward incompatibilities from YANG version 1. This document also specifies the YANG mappings to the Network Configuration Protocol (NETCONF). RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. Informative References

Acknowledgements The author would like to thank Joe Clarke, Reshad Rahman, and Mahesh Jethanandani for their excellent technical reviews, support, and guidance.