Class 3ab1 : showing mintmark type 3 - and a straight-limbed X. The characteristic feature for type 3ab1 being a bust transitional in style between 3a1 and 3b.
Class 3a1 : showing mintmark type 3 - and a straight-limbed X. The characteristic feature for type 3a1 being a class 2 style bust.
Class 3ab2 : showing mintmark type 3 - sharp pointed star, straddling the central crown ornament, and the diagnostic flamboyantly curved X.
Class 3b : showing mintmark type 3 - and a predominantly straight-limbed X, although a slight curvature may be discerned.. The well rounded broad bust is characteristic of class 3b
These four classes all have mintmark type 3 - a sharp pointed star, straddling the central crown ornament.
Class 3ab2 can be recognised by the curved limbs on the letter X, rather than straight limbs.
- Issued at London, Canterbury, Bury, Gloucester, Northampton and Winchester.
The remaining three types have a straight limbed X. Differentiation between them is mainly by bust shape:
3a1 - all types of class 2 bust - issued by only those mints which produced class2 coins - London, Canterbury, Bury, Exeter, Gloucester, Ilchester, Lincoln, Northampton, Norwich, Oxford, Winchester and York.
3b - Characteristic broad bust. Issued by all mints except Durham.
3ab1 - transitional between the above two. Bust less pointed than 3a, but not as rounded as in class 3b.