The NETMOD working group has defined the data modeling language YANG, which can be used to specify network management data models that are manipulated by the NETCONF protocol. The NETMOD working group also defined a number of core data models as basic building blocks. The purpose of the NETMOD working group is to support the ongoing deployment of YANG by (i) maintaining and evolving the core YANG specifications based on usage experience and developing data models that are considered core building blocks and that do not fall into charters of other active IETF working groups (for example a data model for stateless packet filters) The NETMOD Working Group will work on the following items as part of the maintenance and evolution of the YANG language: Y1. A mechanism allowing the usage of custom functions in xpath expressions. Y2. A representation of YANG-defined data trees in JSON. Y3. A mechanism for specifying and advertising conformance levels of implemented YANG data models. Y4. A common definition of YANG tree diagrams. The working group will decide whether Y1-Y3 can be achieved by extensions / updates of the current YANG definition in RFC 6020 or whether it is necessary to revise RFC 6020. In the later case, the working group will consider all defects that have been uncovered since the publication of RFC 6020 and try to address them all. The NETMOD Working Group will not serve as a review team for YANG modules developed by other working groups. All data models must be fully interoperable with implementations of NETCONF and YANG. The WG will consult with the NETCONF working group to ensure that NETMOD's decision do not conflict with planned work in NETCONF. Goals and Milestones: Feb 2014 - Submission of individual draft(s) for custom xpath functions Feb 2014 - Submission of individual draft(s) for a mapping to JSON Feb 2014 - Submission of individual draft(d) for conformance levels Feb 2014 - Submission of individual draft(s) of a stateless packet filter data model Apr 2014 - Submit first working group draft of the stateless packet filter data model May 2014 - Submit first working group draft of custom xpath functions May 2014 - Submit first working group draft of a mapping to JSON May 2014 - Submit first working group draft of conformance levels Oct 2014 - Submit stateless packet filter data model to the IESG Nov 2014 - Submit custom xpath functions to the IESG Nov 2014 - Submit custom a mapping to JSON to the IESG Nov 2014 - Submit custom conformance levels to the IESG