Methods/Standards/Codes This category provides reference to organizations responsible for various methods, standards and codes. Definitions Methods generally describe a systematic procedure or technique to be followed (e.g. analytical testing methods, sampling methods, etc.). Standards are generally rules or measurement specifications ( e.g. water treatment standards, pipe installation standards). Codes typically represent systematic principals or rules (e.g. fire codes, process safety codes). Note: These terms are sometimes used interchangeably.