A serial is issued in parts when each number or issue constitutes more than one physical item. Each part is usually distinguished by numbers or letters and/or an individual title. The parts all have the same common title and usually have the same numeric/chronological designation. (CCM: 17.3.1)
CONSER provides three cataloging options for serials issued in parts.
Create Separate records for each part.
All parts are included on one record with a general 515 note, such as "Issued in parts."
All parts are included on one record with the individual titles listed in a 515 note (this option is less frequently applied).