Underscores in domain part of a url
avril 17th, 2012
Starting with a discussion on stackoverflow with this post and this other post. I search documentation and rfc on the underscore availability in URIs. Old rfc (1994 and before) don’t allowed it, i searched others doc and found this URI rfc where it is mentionned that the underscore character isn’t a reserved character.
In fact, this exists a preferred syntax noted here at preferred syntax but the dns documents seems to be more open Host Names and Numbers. The strongest and clearest too description was made by the rfc on url, which forget the preferred to describe the bnf rules preciselly. There is too 2396
At this moment, i tough this not allowed, but maybe, this is not the problem. In fact, while websphere use it :
- this post mentionned above which speack about internet journal, big site using underscore.
- microsoft, android use underscores in their hostname.
- the dns system permit is as well as apache.