All the books and documents received in the library are taken into its stock by a process called Accessioning which involves the assignment of a serial number called Accession Number. In the case of books donated, they are assigned a Donation Number in addition to the Accession Number. When loose issues of periodicals are bound into a volume, they are given accession numbers. While in some organisations the accession numbers are given to documents after technical processing, in others, its is done first. Once an accession number is assigned, it is deemed to be the property of the library.
Many consider that accessioning is a mechanical process and easy to perform. On the contrary, it requires much experience and judgement. Some of the factors that make accessioning of documents difficult pertain to:
• Definition of "volume"
• Periodical publications