I have noticed several questions about DNS or hosting that would benefit from the asker including the affected domain name. At the same time, I saw one comment that people might not want an SF question to show up in a Google search for their domain name.
It would be great if people were provided with a way to easily obfuscate (and reveal) this information, so that it would be accessible by readers of the question, but not indexed by search engines. Something like ROT13 should be sufficient, although it might not play well with internationalized domain names.
This has already been done on other sites. For example, geocaching.com provides additional hints for caches with ROT13 applied so that you don't accidentally read hints you might not want to know.
My preference would be to implement this in the formatting syntax, using a notation similar to the other block styles. For example:
? My domain name is contoso.com.