Regulations that provide definitions of technical terms and instructions regarding handling of letters of credit (L/C) for smoother trade transactions. Formally, it is called Uniform Customs and Practice for Documentary Credit. Established by the International Chamber of Commerce in 1993, the latest version available presently is the UCP600 revised in 2007.

The four-digit numbers assigned to hazardous elemental substances (for example: Arsenic UN No. 1558) mentioned in the list of hazardous goods specified by the UN Committee of Experts on the Transport of Dangerous Goods, established within the UN. Or, the four-digit numbers assigned to groups of dangerous substances with similar properties (for example: alcohols, not otherwise specifies, UN No. 1987). Presently, numbers from No. 0004 to No. 3506 are assigned. Numbers are not assigned to non-hazardous goods, therefore the articles having assigned the UN numbers can be considered hazardous.
The hazardous goods are classified in the nine categories below:

1. Explosives
2. Gases
3. Flammable Liquids
4. 1. Flammable Solids
   2. Spontaneously Combustible Solids
   3. Dangerous When Wet
5. 1. Oxidizing Agents
   2. Organic Peroxide
6. 1. Toxic Substances
   2. Infectious Substances
7. Radio Active Substances
8. Corrosive Substances
9. Miscellaneous