yaz_syntax() specifies the preferred record syntax for retrieval
This function should be called before yaz_search() or yaz_present().
The connection resource returned by yaz_connect().
The syntax must be specified as an OID (Object Identifier) in a raw dot-notation (like 1.2.840.10003.5.10) or as one of the known registered record syntaxes (sutrs, usmarc, grs1, xml, etc.).