Although it is strongly recommended (W3C source, via Wikipedia) for web servers to support semicolon as a separator of URL query items (in addition to ampersand), it does not seem to be generally followed.
For example, compare
http://www.google.com/search?q=nemo&oe=utf-8
http://www.google.com/search?q=nemo;oe=utf-8
results. (In the latter case, semicolon is, or was at the time of writing this text, treated as ordinary string character, as if the url was: http://www.google.com/search?q=nemo%3Boe=utf-8)
Although the first URL parsing library i tried, behaves well:
>>> from urlparse import urlparse, query_qs
>>> url = 'http://www.google.com/search?q=nemo;oe=utf-8'
>>> parse_qs(urlparse(url).query)
{'q': ['nemo'], 'oe': ['utf-8']}
What is the current status of accepting semicolon as a separator, and what are potential issues or some interesting notes? (from both server and client point of view)