These are the problems we are trying to solve:
1. When we enter an invalid path containing a "@" character to a clean bundle, we get a meta-redirect (<meta content="1; url=/c" http-equiv="refresh" />) instead of the standard 404 response. In Chrome, you can check by typing "view-source:" into the address bar.
This gets a meta-redirect:
This gets a standard 404 page:
We think both should display the same 404 response, and we should not use meta-redirect. Partly because it leads to worse SEO.
2. The URL Redirections tool could handle these URLs as well. However, the "@" character was never allowed in any Liferay version in any type of friendly URLs, it would still be useful to be able to redirect those. E.g.: when a search engine indexed such URLs already.