There are also different sized threads for the left hand lockring (English/ISO 1.29" x 24 TPI), Campagnolo/Phil Wood (1.32" x 24 TPI) and Old French (33 mm x 1.0 mm). The first two are the most common, with the French threading being older, and a little less common.
In addition to the standard sizes, there are alternative thread diameters for left-hand lockrings, including English/ISO 1.29" x 24 TPI, Campagnolo/Phil Wood 1.32" x 24 TPI, and Old French 33 mm x 1.0 mm. The first two are the most frequently used, with the French threading being an older design that is less commonly found.