So this was brought up in the thread about claiming in the nether on the infinity servers and I think it's an issue that needs to be addressed. Recently I've noticed that a lot of people are building elaborate mob killing farms and wither killers in the nether, which isn't a problem if they make it obvious and out in the open. But while trying to mine, I have come across setups that are 100% hidden in plane netherrack, with pretty much no indication that they are there until I pretty much break through them. It's a huge deterrent to me putting a quarry in the nether or mining with anything above a regular pickaxe just in case I happen to break someone's hidden set-up, but there's also no getting around the fact that there are certain things only available in the nether, like nether quartz, ardite, cobalt etc. So basically what I'm saying is we need some sort of guidelines on what should/shouldn't be built in the main part of the nether or what happens if someone's mining/quarrying interferes with someone's structures in the nether, because if we're allowed to quarry in the nether, we should be able to do it without having to worry about accidentally destroying someone's stuff and being accused of griefing. I'm not sure myself what the best way to handle it would be, maybe say that if you need to build something there to do it on the roof of the nether or above a certain height, and then quarrying/mining can happen below that level etc.
Yes they are, I've asked admins about it before, and you can place them, so they're definitely allowed.
Huh strange, the explation I've gotten from staff when I asked about quarrying in other dimensions was "if the system doesn't say the quarry is banned when you try to place it, then you can quarry in that dimension"