PHP Manual: Specifies Element-Set Name for retrieval

bool yaz_element ( resource $id , string $elementset )

This function sets the element set name for retrieval.

Call this function before yaz_search or yaz_present to specify the element set name for records to be retrieved.

Note:
If this function appears to have no effect, see the description of the piggybacking option in yaz_connect.

id: The connection resource returned by yaz_connect.
elementset: Most servers support F (for full records) and B (for brief records).

Returns TRUE on success or FALSE on failure.