Don’t they also utilize semaphore code via bandanas?
ETA: never mind, I was thinking of Men At Work. Or Village People, maybe.
There are a few simple codes, such as the color of the bandanna showing which gang, and how you were it your placement, but I don’t think it gets too complicated.
However, wearing the wrong color bandanna in the wrong neighborhood could get you killed.
There is certainly no pan-Latino whistle code. But there are places where local “whistle codes” do exist, for instance near the U.S.-Mexico border crossings, the vendors and other types who hang out along there use whistled signals. But they are not signals 95% of people here, Mexican or not, can understand.
I would bet the workers in that particular restaurant all come from a fairly specific place and represent a very specific subculture, or they developed that code in the restaurant - probably not to be secretive but just to expedite things over the din of a kitchen.
If in the Canary Islands, no, but Canary Islanders were heavily represented among Spanish settlers in many parts of Latin America, especially Cuba and Puerto Rico.
San Antonio was also largely settled by Canary Islanders in the 18th century.
The word “transliterate” is amusingly and interestingly inappropriate here, but I can’t think of another. I think your prediction is a little too broad: too many phonemes/not enough discrete whistle gestures (another inappropriate only-metaphorical word!), despite, yes, many whistle frequencies are possible. Grammar obstacles…
Or get you peed on (yellow left back pocket). Now you know.
Huh. I’ll look into this. I spent summers in Tenerife for 15 years since the early 70s.