IAB Statement on Identifiers and Unicode 7.0.0
Shawn.Steele at microsoft.com
Wed Jan 28 20:42:07 CET 2015
> With a base character and combination character it was from an IETF point of view possible to create U+08A1 before Unicode 7.0.0, and then U+08A1 was added.
Exactly where the misunderstanding lies. From an IETF point of view it was possible to combine X and Q and to make something that looked like Z. However Z != X + Q, so a different character was added "Z". There never was a way to create U+08A1 before because it's not the same thing as what IETF thinks you can do to create it.
More information about the Idna-update