| I agree, but I'd also add semicolon and colon
characters
| to that list.
...and single, double quotation marks, parentheses, and
dashes.
Double quotes aren't legal in URLs, so they're not an issue.
But single quotes and hyphens are very common and I think it
would be a very bad idea not to treat those as URL chars in all
cases. I'm even bothered a little bit by question marks and
exclamation points, but there is a workaround
([
http://x.com/y? http://x.com/y?]), so I think it will be OK.
I think colon and semicolon would be OK as well.