Cubby's Buses Fleet Numbering System

Cubby's Buses Fleet Numbering System was created in 1935. It includes a fleet code (three digits), its fleet number (three or four digits) and a check digit.

The formats are: Note: 3 denotes an air-conditioned bus.
 * dddd fffx
 * 3dddd fffx
 * dddd ffffx
 * 3dddd ffffx

Fleet type
The fleet type is denoted by its first two digits (or second two digits if 3 is the first digit in an eight or nine digit fleet ID).
 * 06: Volvo
 * 70: Mercedes Benz
 * 71: Scania
 * 72: Guy Motors
 * 73: M.A.N
 * 74: Dennis
 * 75: Alexander Dennis
 * 76: Leyland
 * 77: AEC
 * 78: Mitsubishi
 * 79: Daimler
 * 89: MCW

Subclasses
Subclasses are denoted by second two digits (or third two digits if 3 is the first digit in an eight or nine digit fleet ID). The main class bears 11.

Fleet number
The fleet number is three to four digits and is placed after its fleet code.

Check digit
The check digit is used as the final digit of CBFLS, after its fleet number. It is calculated with Verhoeff algorithm from 1975 to 1989, and Luhn algorithm since 1989. The check digit was introduced in late 1975 following Cubby's Buses buying of Volvo B59s, and spread to other models in early 1976.

Other systems
The same has been applied to other cities.