Out of curiosity, I spent about a half hour researching.
I know what you mean but I could find absolutely nothing.
Of course you have the original programming punch cards from the early days of computing. And they were called just that.
Punch cards.
The only place I have seen that personally is for grading an S.A.T type test where you fill in the little circles.
They would have a punched "answer sheet" that they would lay over top of your work for grading purposes.
Along the way I noticed that there are a lot of more efficient and simpler ways to create/decipher secret messages.
I'm thinking this is something you experienced personally but not something that was ever in practical use.
Sorry, not much help I know.
Peace!
[–] 24186808? ago
Docking.
[–] 24186920? [S] ago
Hmmm... I did a search and it all seems to be pc related. This could be a group of words on a paper, tweet, etc, and the recipient of the message would hold the "punch-card" over the top to parse out the intended message. Is it still called docking?
[–] 24187282? ago (edited ago)
Yes it’s male to male docking. Basically you are using two inputs (male) and using them to produce a single output. Sometimes called “FEC AL Docking” after the person who invented it.
[–] 24187648? 0 points 1 point 1 point (+1|-0) ago
I looked up 'steganography; and 'punch card',
and came up with a method called 'grille'...