ICAO Annex 18 contains general rules for DAC .... the DETAILS on 'classification, carriage, packing, labelling and documentation' are contained in 'ICAO Technical Instructions for the Safe Transportation of Dangerous Goods by Air' (ICAO Doc 9284) ..... so in general, general rules in Annex 18 .... the DETAILS (on documentation, on packing etc) in Technical Instructions.