[Richard Crowley]

"fudgee logic" wrote ...
OK, I think I've got it. An adapter (or "adaptor", "coupler", "gender
changer") should be described by the connectors it actually contains
rather than the connectors which it mates with.

Can I now ask about another related usage which also confuses me. As an
example, let's say I have an adapter which has an RCA-phono socket and a
3.5mm jack plug.

Some suppliers leave out the terms "socket" and "plug". So in this
example, what is the common usage:

(a) "RCA-phono to 3.5mm jack".
(b) "3.5mm jack to RCA-phono"

(c) Female RCA (Cinch) to male 3.5mm phone (mono)

* "phono" is too easily confused with "phone"
* the original "RCA phono" connector is also known as "Cinch",
particularly outside the US.
* "socket" and "plug" (and "jack") are not necessarily defined properly
by the public. For that matter "male" and "female" are not always
identified properly because male connectors often have pins recessed
into a female-looking shell. (No anthropomorphic implications intended.
:-)
* each end must be precisely and completely defined, not left to assumption
if that is done, then the sequence is not significant, although common
convention is to state the female end first (presumed to be the "input")
* "mini-phone" is no longer assumed to be 1/8 inch or 3.5mm since
there is increasing use of similar-looking 2.5mm connectors, etc.
* phone connectors (of whatever size) should be specified at least as
"stereo" vs "mono", although there is growing use of 4-pole versions
(for stereo headphones + microphone, or stereo audio + video, etc.)
and 3-pole does not necessarily imply "stereo" either, as it is commonly
used for audio + power (as for mono computer "mic input"s)