To quickly answer your questions, that is the "do my research and see what I can find on wikipedia answer to shorting", lol.
Yes, there are many, if not all will let you short a security. Each brokerage is different with rules and what they will allow/execute on each market/exchange.
Interactive brokers and Trade Zero are two that are more liberal and will do OTC, but not the only ones. I personally utilize three different brokerages depending on what I am trading.
Best of luck to you....
I am sure you will have follow on questions....and the answer will always be "it depends". You have to be very specific, detail oriented, and when you get to that level, will require personal information, which you will likely not get in an answer, especially if coming from this person...
Cheers
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