A user contributed this solution to using sh404SEF with FlexiContact:
1.) Lookup the Flexicontact URL and ID in the Joomla menu manager. My URL was "index.php?option=com_flexicontact"
2.) Open the sh404SEF URL manager and create a new URL. Enter your desired SEF URL and then for the non-SEF URL rewrite the URL from step #1 to include the ID number (index.php?option=com_flexicontact&Itemid=XXX) where XXX is the ID number. Save. (Note that sh404SEF will rewrite the non-SEF URL to include the language "index.php?option=com_flexicontact&Itemid=188&lang=en")"
This may or may not be helpful for our other extensions.
Several users have indicated that they would like to use sh404SEF to add meta keywords to specific pages in order to improve their search rankings. This is a misconception, as described in this Google blog:
Google does not use the keywords meta tag in web ranking