The most common capitalization scheme seen with acronyms is all-uppercase (all-caps), except for those few that have linguistically taken on an identity as regular words, with the acronymous etymology of the words fading into the background of common knowledge, such as has occurred with the words scuba, laser, and radar—these are known as anacronyms. Anacronyms (note well -acro-) should not be homophonously confused with anachronyms (note well -chron-), which are a type of misnomer.Re anachronyms ("misnomers"):
- The "lead" in pencils is made of graphite and clay, not lead; graphite was originally believed to be lead ore, but this is now known not to be the case. The graphite and clay mix is known as plumbago, meaning "lead ore" in Latin, and is still known as "black lead" in Keswick, Cumbria and elsewhere.
- Blackboards can be black, green, red, blue, or brown. And the sticks of chalk are no longer made of chalk, but of gypsum.
- Tin foil is almost always aluminium, whereas "tin cans" made for the storage of food products are made from steel with a thin tin plating. In both cases, tin was the original metal.
- Telephone numbers are usually referred to as being "dialed" although rotary phones are now rare.
- In golf, the clubs commonly referred to as woods are usually made of metal. The club heads for "woods" were formerly made predominantly of wood.
The term anachronym (note well -chron-) as defined in Garner's Modern English Usage refers to this type of misnomer... Anachronyms should not be homophonously confused with anacronyms (note well -acro-), which are words such as laser and sonar that have acronymic origin but are generally no longer treated like conventional acronyms (that is, they are used syntactically like any other words, without obligate reference to their original expansions).You learn something every day. More at the links for the wordsmiths on this blog.