rtfd/readthedocs.org — Issue #148: Underscores should be omitted or mapped to hyphens in hostnames
Author: ncoghlan
Created: 2011-12-11 12:28:17+00:00
State: open

This link confuses the Twitter URL shortener (i.e. it refuses to shorten it):
http://ncoghlan_devs-python-notes.readthedocs.org//en/latest/pep_ideas/index.html

This one works fine:
http://readthedocs.org/docs/ncoghlan_devs-python-notes/en/latest/pep_ideas/index.html

RFC 1123 restricts valid hostname characters to letters, numbers and the hyphen (i.e. no underscores allowed), so the Twitter shortener is actually doing the right thing in rejecting the first URL. It should really be:

http://ncoghlan-devs-python-notes.readthedocs.org//en/latest/pep_ideas/index.html

or

http://ncoghlandevs-python-notes.readthedocs.org//en/latest/pep_ideas/index.html