Thread:Extension talk:MobileFrontend/OpenSearchXml required?

The page says "Note that the current implementation of the javascript search on the mobile site requires Extension:OpenSearchXml to work."

However, I just upgraded espiral.org to 1.20.2 installing the current snapshot from master and it seems to work without installing Extension OpenSearchXml? I mean, I get suggestions of pages as I type in the search box. Is that what you mean or is there more you would get by installing also OpenSearchXml?