[dns-operations] xn--

[John Levine]

It appears that Gihan Dias <gihan at domains.lk> said:
>Could anyone point me at a description of how xn-- was chosen for the 
>prefix for idn domains, and how we could register a similar prefix for 
>another application?

See RFC 3490, section 5.  They excluded eight prefixes that had been used
in previous documents and picked two letters at random.  RFC 3797 says they
used the same random selection algorithm they use to pick IETF nomcom members
from the pool of applicants.

To reserve another prefix you'd need an IETF standards track RFC that describes
what the prefix is for and how it's used, similar to what RFC 3490 does for
IDNA.  It would be a good idea to pick the two characters the same way, randomly
to avoid people squatting on them.

The first step to an RFC is to write an Internet Draft describing in detail
what you're proposing.

R's,
John