i want to know if the search engines like google indexes the metadata encoded in xml formats like EAD, TEI,.. or are these data considered part of the invisible web because each institution of conservation of ressources uses a format different and they have sites in which there is a searching interface and it is known that data which is accessible through a searching form is part of deep web ?

Also, another thing that makes me confused is that when I typed the query “Ibn sina manuscript” in Google and I got a link to this manuscript in their site (BNF archives and manuscripts) whereas Google doesn’t index the deep web like manuscript catalogs and normally it will not show me this manuscript and to get it I have to enter this site and search for it. How do you explain this?
Thanks in advance.

please explain to me this point