Whenever the following characters appear in an URL in a link of the form [foo][1] … [1]: http://..., the server won't parse it as URL:
^,{,},\
and the following won't work in preview:
$,^,*,[,],{,},\,',"
This causes great trouble when copying links from the URL bar. Browsers seldom escape every character, e.g. in Firefox ~!^*_-{}|[]\. in a query string will not be escaped, while in Chrome ``~!$^*()_-{}|[]:;',./won't be escaped. For example, [all 3 Wolfram Alpha links by this user](http://math.stackexchange.com/posts/1911/revisions) fails to appear because of^,{and}`. Fixing these links are annoying.
Therefore, I propose that when one creates a link or image through the toolbar (Ctrl+L / Ctrl+G), the system should be able to escape at least the above mentioned characters.
<http://en.wikipedia.org/wiki/IDA*>(Maybe a clash with the Markdown for italic?)