Dangerous goods list, special provisions, limited and excepted quantities
Reading Table A
Chapter 3.2 Table A is the operative list. For each UN number it gives the proper shipping name, class, classification code, packing group, label models, special provisions (Chapter 3.3), the limited quantity value, packing instructions and special packing provisions, mixed packing provisions, and tank/portable tank instructions with their special provisions. The alphabetical index gets you from a trade name to a UN number; the name you then use on documents and marks is the one in the list, with any technical name required by special provision 274 added in brackets.
Special provisions
Chapter 3.3 provisions attach conditions to individual entries - some add requirements (technical names, restrictions on damaged or defective articles), some grant relief. They must be checked entry by entry; a special provision can change what a packaging instruction appears to permit.
Limited quantities (Chapter 3.4)
The Table A limited quantity value (0, 1 L/kg, 5 L/kg and so on) caps both the inner packaging and the gross mass of the package, and the chapter sets out the LQ mark. Labelling, placarding and orange plates are not required, but the goods are still dangerous goods: correct classification, suitable packagings and a compliant document remain mandatory. A value of 0 means no limited quantity use at all.
Excepted quantities (Chapter 3.5)
Codes E1–E5 permit very small quantities per inner packaging and per package, marked with the excepted quantity mark. Excepted quantities go further than LQ in removing marking and documentation requirements, but the quantity ceilings are far lower.
Worked example
Twelve cartons, each holding 4 × 1 L bottles of UN 1263 PAINT (Class 3, PG II, limited quantity 5 L). Inner packaging 1 L ≤ 5 L, contents per carton 4 L within the package limit: LQ is available, so the cartons carry the LQ mark instead of labels. If the entry instead showed 0, each bottle would need full labelling and the load full placarding.
Traps
Treating LQ as unregulated; forgetting that LQ and excepted quantities are different chapters with different marks; ignoring special provisions when planning a load; assuming LQ relaxes packaging quality.