This post assumes that you read the article that I linked in my previous post. I re-read that article again last night, and I want to address some points in that article (which is still very fascinating to me).
First, why did the author call it SS/YL? And whatever happened to the Cuban lady? Is she still going on? What have we learned about it?
When I was active in shortwave clubs, the bulletins used a lot of abbreviations. The English language ws EE. Spanish? SS. One club used EG and SP, but the two other major clubs stuck with EE and SS. I can't tell you why one club did it their own way. YL? Young lady. Ham radio operators, regardless of age, are either OM (Old Man) or YL (Young Lady). Married YLs become XYLs (ex-Young Ladies). At the time the article was written, this numbers station didn't have a name. Thus the author coined SS/YL.
It was also known in the shortwave circles as the "Atención station" due to its callup, and later on a numbers monitoring group gave it the designator V2. V for voice, and 2 to identify it as a specific voice station. Later on it was re-designated V2A due to a format change with a minor variant in.....was it 1986?
The callup became something like "Atención! Tres siete cuatro....cero uno" several times, and then for three times something like "cero uno.....cuatro cinco"....which in this example is 01-45, where 45 is the group count. I sometimes would notice double messages. Let's say 926-05-00, then a 05-78 message, followed by a 00-95 message......78 groups followed by 95 groups. Why there were two messages is anybody's guess.
I wasn't active in shortwave listening for a long while, but I knew the numbers stations kept going even after the end of the Cold War. The V2 station was one of them, and no evidence as to their purpose surfaced until the late 90s. In 1998 a spy ring was broken up, and it emerged that those involved got their instructions via shortwave radio, and yes, it was from V2. Evidence of the one time pads for decryption was presented, and the perps were convicted and served time. What was never made clear was if the messages were in English or in Spanish, but it was proven that yes indeed, the station was transmitting messages to spies.
Now it stands to reason that not all of the messages were for spy traffic. There's no doubt in my mind that a percentage of this had to be dummy traffic, so that NSA resources would be used for trying to decode them. Other messages might have been for training purposes. This is speculation on my part, but I'd be comfortable betting money on this.
So where is V2 today?
Still in commission, but now it's designated HM01. I tuned in yesterday to hear a transmission. A voice callup is still used, but instead of group counts, the station now sends out data bursts which are in computer file format. I looked at a decode of one message and saw both Japanese and Chinese characters in the decode. From what I could tell, it was random. So are the spies now using new tools?
I'm not sure. My thinking is that the message traffic is now intended for military and embassy operations. The messages continue for several weeks on end without changing. The transmissions are also nowhere near as frequent, though still daily, and still on a fixed schedule.
There is still a fascination within one segment of the shortwave radio listening hobbyists about these mysterious numbers stations. There were many others, some no longer active. A search engine will yield several hits where you can learn more.
You also don't need to buy a shortwave radio to get in on the fun. Look up Kiwi SDR, and take it from there.