Simple Q: how much identifying info can be gleaned from the tape regarding who is behind options transactions? For equities, I'm pretty sure that some sources show you the executing brokerage (certainly not the individual account holders), but I've been unable to find similar info for options Time & Sales. Is it possible to see any identifying info about who or which brokers are on each side of options trades, and if so: how?
With absolute certainty - no. Unless you get someone drunk at OCC. Ask your broker how they route and now you've got a decent chance it was the DPM unless they have a preferencing deal. Preferencing deal makes it almost certain if they want to share. If there is an out or a bust which is rare - then your broker would know who was on other side. U.S. securities options - other parts of the world are different.
Although not the information you asked about, the new enhanced option time and sales information is very useful (available about a year ago). I have noticed not all brokers are offering it. Basically there is an identifier next to each transaction saying what type of trade it is, I believe around 20 or so. Examples are SLAN (single leg auction) MLET (multiple leg electronic trade) MLEF (multiple leg floor trade), etc. So you can tell if a trade is a cross, if it was done on the floor, if it was a spread, etc.
I know it's not what you are looking for, but there are other markets where it's possible (for Futures, Stocks, Options etc.) and it's sort of default. In Brazil, for instance, blind brokering is an exception.