This is actually the quantity assigned in your write-up from the publisher, and it's the 1 you are going to use to reference your article in the library catalogues. ISSN code (also referred to as as "ISSN construction" or "ISSN syntax") is often expressed as follows: NNNN-NNNC Later on, in https://www.directivepublications.org/journal-of-applied-nanoscience/