Internal Local Format 

Internal formats are so called because they are internal/local to a software system. They can be changed specifically as per the needs of the local system and do not have to conform to any external standards. For the internal format (the identifiers used and their records structure), system designers can adopt any conventions that they wish. Rules for input are more restricted, being constrained by existing cataloguing codes and practices' and need to be compatible with other systems or with a standard exchange format. Their main aim is economy and efficiency in processing, while the ability to convert, if necessary, from the local format to an exchange format is an extra advantage. This conversion can be done by computer programme. An agency may, therefore, adopt its own internal processing format, but at the same time retain system compatibility with a national or international exchange format. Internal formats can be structured in infinite varieties or ways which depend on the software used.