The abbreviation “CBC” is not an acronym. Really.

Acronyms and initialisms are abbreviations made from the initial letters of words in a name. An acronym spells a pronounceable word (“UNICEF”); an initialism does not (“CBC”).

Some pronounceable abbreviations never become acronyms: “B.A.,” for example. And some initialisms acquire unofficial but popular pronunciations, such as “Icky-bicky” for ICBC (Insurance Corporation of B.C.). Are there any rules or conventions for abbreviations that stubbornly stay in the corral when the gate is open, or those that slip out through a loose board when no one's looking? All input welcome!