Unit introductions

The unit introductions show which headings in a particular unit have changed at each new key edition (starting every 1 January). From 1 January 1994 only those parts of the UKC which have been amended have been republished.

The latest edition of every heading are on this website and the unit introductions serve to let the user know which headings have changed.

Section A

• Divisions A1-A3 (24Kb)
• Division A4 (24Kb)
• Divisions A5-A6 (25Kb)

Section B

• Divisions B1-B2 (26Kb)
• Division B3 (25Kb)
• Divisions B4-B5 (25Kb)
• Division B6 (25Kb)
• Division B7 (25Kb)
• Division B8 (28Kb)

Section C

• Division C1 (24Kb)
• Division C2 (25Kb)
• Division C3 (28Kb)
• Divisions C4-C5 (24Kb)
• Divisions C6-C7 (25Kb)

Section D

• Divisions D1-D2 (26Kb)

Section E

• Divisions E1-E2 (26Kb)

Section F

• Division F1 (27Kb)
• Division F2 (27Kb)
• Divisions F3-F4 (25Kb)

Section G

• Division G1 (25Kb)
• Divisions G2-G3 (26Kb)
• Divisions G4-G6 (26Kb)

Section H

• Division H1 (27Kb)
• Division H2 (27Kb)
• Divisions H3-H5 (27Kb)

Notes

To make it clear when particular pages of a heading key were last amended they carry a two part folio mark as explained below.

• The letter before the slash represents the latest Key Edition at which that page was reprinted.
• The letter or number after the slash represents the Key Edition at which that page last had a change of substance.

Pages republished to correct printing errors may carry an "(e)" at the bottom right-hand corner.

Classification and indexing marks may carry a (left) marginal letter. The marginal letter indicates the key edition at which that mark was added to the classification key.