Hi Vladimir,
Thanks for the feedback! I think it's a really useful component too (but I'm a bit biased ;-)
Regarding your question,
If the first processing steps do not redirect to the correct URL, or the correct URL cannot be found then 404 redirect performs a search.
At the moment, the search uses the longest part of the URL after the domain name as the searchterm. Usually, the longest part of the URL is the page title but I realise it's not always the case.
So, in the next version I'll include a check to test if the searchterm is in the list of joomla categories and sections and if so, search on the next part of the URL (if it exists)
e.g: mysite.com/section/mycategory/page.html =>
'mycategory' is longest (10 characters) but because it's a category, I'll make it search on the next part of the URL ( page ).
Look for an update version next week,
have a good weekend :-)
David T.
P.S Nice site!