No I'm not talking about some kind of secret handshake to identify us as a Hapkido secret society, but a standard way I was taught to shake hands as a martial artists.
The standard guy handshake is firm and all to often just plain to firm. Kinda like "If I don't break bones, I'm not a man" kind of firm.
I was taught and teach a standard handshake that keeps the hand more relaxed to keep the muscles more reactive. The pointing finger is extended down the length of the forearm to keep it ready for a Ki finger and pressure point availability. At the same time it puts your knuckles off line in your opponents grip so that they can not squeeze your hand squishing and grinding you knuckles together.
There is also what is called a master's handshake, in which you cup the back of the opponents hand with your Ki finger pointing downward at about a 7-8, 5-4 position.
The thing is that more than once I have shaken someone's hand and been mistaken for a Freemason handshake. I can't remember it off the top of my head so far, but I would shake someone's hand and they would recite the mason phrase to identity each other.
I would just look at them when they say their thing and smile, telling them that I was not a mason, but a professional martial artists and then explain my handshake to them.