This is actually the amount assigned for your write-up with the publisher, and it's the one you are going to use to reference your write-up in the library catalogues. ISSN code (also referred to as as "ISSN composition" or "ISSN syntax") may be expressed as follows: NNNN-NNNC SJR The SJR https://www.directivepublications.org/journal-of-applied-nanoscience/