What is the shortest reserved (example) domain

Question

IANA has a list of reserved domains, in tests and documenation. Most famous are probably example.com and example.org.

For documentation and designs of a system that uses very short URLS, I'm looking for a t.co or bit.ly equivalent. I could not find any short ones on that IANA resource.

What is the shortest possible, offical "example" or "reserved" domain and therefore URL?

Answer 1

The document you refer to refers to RFC 2606 that lists all reserved domains that are four TLDs:

     .test
     .example
     .invalid
     .localhost

and three second level domains:

    example.com
    example.net
    example.org

The shortest of them is .test TLD.

Domains like t.co and bit.ly are real domains with single letter second level domain and regular to letters TLD.