A 29 year old male patient complains of protruding upper incisors. The incisor relationship can be classified as Class II div 1. This system of classification for incisor relationship was described by:
British Standard Classification of Incisor Malocclusion:

Class I: The lower incisor edges occluded on or lie below the cingulum plateau of the upper incisors. 
Class II, division 1: The lower incisor edges occluded behind the cingulum plateau of the upper incisors and the upper incisors are normally inclined or proclined. 
Class II, division 2: The lower incisor edges occluded behind the cingulum plateau of the upper incisors and the upper incisors are retroclined. 
Class III: The lower incisor edges occlude anterior to the cingulum plateau of the upper incisors.

Ref: British Standards Institute. Glossary of Dental Terms (BS 4492). London: BSI; 1983.
E. Angle
British Standards Institute
Ackerman-Proffit system
Dewey