I can agree with experienced pilots getting annoyed with what happens around the circuit, and my observations are that some pilots partially miss the point of circuit area calls.
Many pilots think that the call is to state intent, and that the other words thrown in are just part of the 'jargon', not realising that part of the call is also to state location.
There are then parts of the 'jargon' that tend to be defined by accepted norms rather than hard definition on paper.
Trying to fix that situation runs into a double edge sword which has us adding more words to the call, which at a busy airfield (or in my situation of two airfields in reasonable proximity, on the same frequency), can quickly fill up the airwaves with constant chatter.
Case in point, the word 'downwind' can be used on it's own, or prefixed by a choice of four other words; Joining, turning, mid or late.
The 'unwritten' rule has the singular word on it's own, is used in between turning and mid.
All four variants state the same intent, but individually, they all propose a fairly specific location except 'joining', which can be a red herring.
So, if you say;
Turning down wind, you're at that point (already in a circuit) going from crosswind to downwind, supposedly out roughly at a forty five degree angle from the end of the strip you took off from (angles may vary...)
Downwind, on it's own, suggests (colloquially) that you are between turning and mid downwind, which leads to;
Mid downwind, which has you halfway along the strip.
Late downwind, means you either forgot to call downwind or couldn't get a call in due to radio traffic, but you're about to turn Base anyway.
The tricky one is;
Joining downwind, with no other locative word, implies you are new to the circuit at roughly the 'turning downwind' point.
If you want to 'join' the circuit at any other point, that position needs to be stated, to give a position to your intention.
So, 'joining mid downwind' and 'joining late downwind' define an intent and a location.
Some slightly confusing prefixes are 'long' and 'early' downwind.
Joining long downwind implies you are actually further upwind in the circuit than the crosswind position, and intending to fly into the circuit for the first time.
If for some reason you had to extend your upwind after takeoff, and want to let others in the circuit know that you're still technically in circuit (but breaking out the VTC), then you can call;
Turning wide crosswind when you change from runway heading, or just;
Turning long downwind as you pick up the downwind leg direction.
Saying Early downwind is just confusing, but is really the word to use between 'turning' and 'mid' if you don't want to use the statement 'downwind' on it's own.
See, clear as mud!
I blame all errors on it being late, and that I should be in bed![/i]