Cryptsy has a lot of markets. Each market has its own ID. Now markets have an ID in the range [1,220]. Sometimes old markets are deleted. Are the IDs of that markets reused or not?
I have the same question for Bittrex and MintPal
They don't reuse market IDs. For example, SaturnCoin (SAT) has been deleted and replaced with SAT2. That was market ID 168(search for cryptsy. It links to https://www.cryptsy.com/markets/view/168). If you want to go there, you'll be redirected to the home page. SAT2 has market ID 233. Why wouldn't they replace SAT/BCT with SAT2/BTC? Anyhow, market 248 (latest at the moment) does also exist, which is later introduced then SAT2 and probably also later then the removal of SAT. Based on this, I think I can safely say they will not reuse the market IDs. And why would they? It will only be confusing and frustrating.
For the other two exchanges, I am 100% sure they will not reuse their IDs. If you go to a specific markets, the url consists of something like
BC/BTC. Unless their is some new coin stupid enough to launch with the same abbreviation , there is no chance it will have the same ID.