AUTHORSEPS is a wrapper for the separators between authors. It holds the TWOSEPS and THREESEPS elements.
<AUTHORSEPS> <TWOSEPS> and </TWOSEPS> <THREESEPS> <THREESEPSEACH>, </THREESEPSEACH> <THREESEPSLAST>, and </THREESEPSLAST> </THREESEPS> </AUTHORSEPS>