* There is no word in English dictionary with HH (°°°° °°°°). Hence it's a code to indicate scratch the last word.
* The washing machines & microwaves of many manufacturers often beeped AS (°-°°° i.e. Wait) in Morse when they were done, to indicate machine is "standing by"
Beachhead
'Ahh uhh' etc aren't useful in a mode of telegraph communication which is rather very terse & commonly does not even include is/are/and etc in transmission. Pithy sentences relaying the content matter is encouraged - to speed up typing & also not to block useful airwave. Most HAMs are sharing a narrow set of channels & only one operator pushes-to-'talk' at any given time
I once knew a HAM that went by Gark in Morse because it was faster to key than Gary.
Using morse is all about efficient transmission in high noise environments.
Personally, I think I'd be annoyed if i had to decode that whilst sitting on a mountain top, or wherever (not being hyperbolic SOTA[1] and POTA[2] are real things folks participate in).
[1]: Summits On The Air https://www.sota.org.uk/ [2]: Parks on the Air https://parksontheair.com/
The poster earlier claimed that no English word contains the digraph "hh", however, which is simply untrue. It's quite uncommon, and I'm sure the prosign use of HH is grammatically unambiguous in general, but it being invalid otherwise is not a well-founded reason.
Context, my friend.
If you pick up regular non-colloquial words & unconjugated words, there actually is no word with a double H. I read this trivia in the ARRL handbook. Extremely well written covering everything HAM.
But like others are posting to prove a point in contrary, fishhook beachhead exist - but are either conjugated or colloquial. By that reasoning, every second word in Asian languages such as Vietnamese/Laotian has double H when scripted - but is it to be considered a standard mode of unambiguous communication over international frequency spectrums?
> [...] a standard mode of unambiguous communication over international frequency spectrums
That's exactly the context that's missing for most participants in this thread :) Thanks for making it explicit for us! When you lead with "There is no word in English dictionary with HH", it sounds like the context is literally the English dictionary. What you're actually judging against is the practical lexicon of radio operators, which is very different and worthy of investigation independent of the lexicon the rest of us plebians use ;)
> Beachhead
Also bathhouse, fishhook, hitchhike, roughhouse, and withhold.
From http://lidscw.org/resources/cq-qso-template
> There are three in general use: AR signifies the end of the message, KN marks the end of your transmission and an invitation to the other station to reply, and SK says it’s the end of the contact and your last transmission to that station
See this nice discussion on the nature of morse:
https://cs.stackexchange.com/questions/39920/is-morse-code-b...
> TLDR: We can thus conclude that the Morse code can be understood, and easily analyzed, as the composition of a prefix binary encoding of a 3 symbols alphabet {dot, dash, sep} into a binary alphabet, and a prefix encoding of a 58 symbol alphabet (57 characters and one space) into the 3 letters alphabet.
> The composition itself is a prefix encoding of the 58 symbols into a binary representation.
Check this part:
> However, some people would be inclined to recognize the space DET at level 2, thus making the alphabet quaternary, then using it directly at level 3, encoded as itself in level 2.
> This would meet the standard definition, for DET encoded in binary as 0000. But it would prevent the analysis of the binary encoding C2→1 as a prefix code, making it harder to show that CMorse is a prefix code, hence unambiguous.
In your link, AR, KN and SK can be considered in a similar way, but applied to the decoded message.