I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG.  These comments were written primarily for the benefit of the security area directors.  Document editors and WG chairs should treat these comments just like any other last call comments.

This is an easy one. It proposes reclassifying an Informational RFC to Historic. There are no non-trivial security considerations.

RFC2482 is an informational RFC describing an escape sequence in UTF* character encodings to embed language tags. While the history of the feature is not clearly stated in the document, it appears that this was an up-and-coming feature in the ISO10646 / UNICODE world at the time RFC2482 was submitted, but that it since has fallen on hard times and is now The UNICODE Consortium strongly recommends against its use. The original proposal had no security considerations, and this document notes correctly that not using the feature can only improve security. The authors of the new document include the authors of the old, so this is unlikely to be some sort of turf war.

Other notes:

RFC2482 said:

   This document has been accepted by ISO/IEC JTC1/SC2/WG2 in meeting
   #34 to be submitted as a recommendation from WG2 for inclusion in
   Plane 14 in part 2 of ISO/IEC 10646.

It would be good to note whether WG2 ever accepted the proposal and whether either ISO/IEC JTC1/SC2/WG2 or WG2 have officially deprecated it to reassure the reader that there is no controversy over its status in those communities.