EDCS Attribute Codes, however, answer the question, what are its additional clarifying characteristics? (For example, it's a lighthouse, it has a depth of 1.5 m, it's red, it's an oak tree.)

EDCS Attribute Codes (EACs) are non-hierarchical. An EAC is a 4-character encoding (2-3 alpha, 1-2 numeric). Codes are generally based on mnemonic abbreviations, e.g. BFC_ is used for Building Function Category.

Choose the initial letter of the code you wish to refer to.