B Intermediate managerial, administrative and professional
C1 Supervisory or clerical and junior managerial, administrative and professional
C2 Skilled manual
D Semi-skilled and unskilled manual
E Casual labourers, state pensioners, the unemployed
These categories are sometimes grouped as four grades (e.g. in reports of newspaper readership), thus: AB, C1, C2 and DE, sometimes as three groups (AB, C1/C2 and DE) and sometimes as two groups (ABC1 and C2DE).
Since only a small percentage of the population holds the top jobs and the proportions tend to increase towards the bottom of the list (at least if we lump together the lowest categories) this division is often represented as a social pyramid.
For audience figures based on such categories see here.
