The IDNA protocol standard is currently under review and revision. An informal expert panel, working as what the IETF calls a "design team," evaluated experiences gained in the implementation of IDNA since its introduction in 2003, and identified several key areas of future work. These were described in particular in RFC4690 that triggered a formal revision of the IDNA protocol. The core components in the revision effort include: definition of valid IDN labels, an inclusion-based model that recognizes the level of understanding of the implications of the Unicode handling of various scripts on use in IDNs (the current model is exclusion-based), elimination of confusing and non-reversible character mappings, fixing a right-to-left error in Stringprep, and eliminating Unicode version dependencies, thereby permitting more scripts to be used in IDNs now and in the future. The issues with the current IDN model that led to the revision work are discussed in RFC4690.

Latest version of the IDNA revision proposals are available through the IETF or at Patrik Fältström’s site: http://stupid.domain.name/idnabis/