Internet Standards (RFCs) relating to IDNs

List of selected RFCs relating to the subject matter of Internationalized Domain Names in Applications (IDNs), that is domains including umlauts and accents:

RFCs zu IDNs
RFC 3492Punycode: A Bootstring encoding of Unicode for Internationalized Domain Names in Applications (IDNA)
RFC 5890Internationalized Domain Names for Applications (IDNA): Definitions and Document Framework
RFC 5891Internationalized Domain Names in Applications (IDNA): Protocol
RFC 5892The Unicode Code Points and Internationalized Domain Names for Applications (IDNA)
RFC 5893Right-to-Left Scripts for Internationalized Domain Names for Applications (IDNA)
RFC 5894Internationalized Domain Names for Applications (IDNA): Background, Explanation, and Rationale
RFC 6452The Unicode Code Points and Internationalized Domain Names for Applications (IDNA) - Unicode 6.0

You find a complete list of all RFCs in the RFC archive of the IETF and on the RFC editor website.