If you want to link to a tag search such as the following:
https://stackoverflow.com/search?q=[xml]+[php]+parse
It won't create a link unless the square brackets are URL encoded. That is, this doesn't work:
https://stackoverflow.com/search?q=[xml]+[php]+parse
But this does:
https://stackoverflow.com/search?q=%5Bxml%5D+%5Bphp%5D+parse
Would it be feasible to automatically URL encode these links?