When handling general mobile notary work, I receive calls for documents I many times do not recognize. Recently, I received a call to notarize an FS-240 form. I wasn't familiar with this form so I looked it up and saw it is a vital record, just like birth records here in the US. It is for US citizens who have children born outside of the US. However, to get a copy of it, a notarized statement with specific information is required and then mailed to the Dept. of State, Passport Division.
Just like a US birth certificate, only the agency where it is issued can certify the copy. And just like a birth certificate request, we need to discern what the client really needs or we may refuse a legal request. The document to obtain the record is notarized and any notary can handle that request. What we cannot do is certify a copy of one or have them write a statement about it and attach a certificate.
Here is my tip. Whenever I am asked about documents I have never handled, the first thing I do is "google" them to see what they look like, including if there is a place for signature and notarial wording. Then I am more comfortable accepting the request and know for future reference what it is about.
At your Service,