Domain registries, particularly those implementing IDNA (RFC 5890 
et.al), usually maintain a set of criteria (or "ruleset") that governs 
permissible labels allowed for registration, such as [IANAIDNTABLES]. 
These rulesets are commonly a mixture of eligible code points along 
with contextual criteria that must be met concerning the positioning of 
certain code points. Some registries also specify rules regarding 
variant labels and how they are to be handled. Domain registries 
commonly need to share these rules, but there is no interoperable format 
that can be used that can support many common use cases. This group 
seeks to produce such a format, which will enable re-use and sharing of
existing rulesets, and simpler implementation of new rulesets in registries.

A comprehensive format specification has been developed, named Label
Generation Rules, primarily to support the rules to be used for the 
DNS Root Zone [Davies]. This group will use this specification as a 
starting point to develop a common XML language that provides a superset 
of functionality of current specifications
[RFC 3743, RFC 4290, et.al], along with other known use cases. This 
single format is expected to supersede existing formats, and form the 
basis for future rulesets used at different levels of the DNS hierarchy.

Work items:
- Standard Track Specification of the Label Generation Rules

References:
[Davies] https://datatracker.ietf.org/doc/draft-davies-idntables/
[IANAIDNTABLES] https://www.iana.org/domains/idn-tables