Registering 2 letter second level domain

    Does anyone know if there is any imperative (writen or oral)
    to avoid registering 2 letter second level domains? 
    I know some top level domains refuse to do so based on possible
    conflicts (due to user misconfigurations) with current or future
    top level domains, but others allow it.
    We have a request to register one of these under "es" and I want
    some advice before saying "yes" or "no".
Forbidding to register 2-letter subdomains is pretty hard,
but people should *strongly* be advised *not* to register
2-letter subdomains. Practice has shown that people overlook
or don't know what RFC822 states in par. 6.2.2, and in their
ignorance allow abbreviated addressing. I've seen *LOTS* of
mails meant to stay within a CS department, being routed to
[the former] Czecho-Slovakia, because there is no way to
distinguish between an internal address user at foo.cs (where
the FQDN is foo.cs.xxx) and an external address user at foo.cs
in Czecho-Slovakia.
In your case I'd say registering a domain es.es is almost a
guarantee for troubles.


	Piet