Mac Server G3 300 Minitower

The MPN (Marketing Part Number), also sometimes called the model number, marketing number, order number or part number. This is the part number under which Apple sold this particular Mac model. Only base configurations have part numbers, while Macs sold with various build to order/configure to order options do not have them. What we consider a single Mac may have multiple part numbers, which may refer to different specifications of RAM, drive size, or case colour that were offered as base options. Part numbers also differ by country or region.

In modern Macs it is usually an 8 or 9 digit code, with the last 2 characters being "/A" or occasionally "/B". The one or two characters immediately before the "/" depend on country or region - "B" is the UK, "LL" the USA, etc. We represent this portion as "xx".

Model numbers, also sometimes called family numbers, are an identifier that often cover a fairly wide range of Macs. In cases where the fundamental design of a Mac has remained mostly unchanged, but incremental upgrades have been made to internal components, a single Model Number can cover more than 20 individual Macs, released over several years. Other Model Numbers are unique to a single machine.

It is usually a 5 character code in the format AXXXX, where the Xs are numerals. Some very old Macs have a Model Number that starts with an "M" rather than "A".