This BUG was implemented again, I believe, to fix some aggression/flagging bugs, while it otherwise nerfed one of the game play mechanics of fields. I want to say this bug came back into play closer to 2008-2009, but I'm still looking for the research I submitted to the bug submissions site about this a few years back.
I'll try to get some more information and a better timeline on the change. I don't even know when the first time this happened was, it was the time where any damage done to a target changed your current target additionally putting you in war mode. Or run an archer/tamer, attack one target and send your pet on another and see where your arrow lands. When it came around this time I remember getting really frustrated with poison fields (this was after naked nox mages were cool, and before the changes to bring back the nox mage like a year or so ago). Put 20 monsters in a poison field and try to target one in hand to hand combat.
If you walk into a field while in stealth mode the chance of being revealed is based on your hiding/stealth. If I cast a field and someone or something walks into my field my meditation is broken or if I am hidden I am automatically revealed. In the past, 3-4+ years ago, you were flagged to the player walking into the field but would remain hidden or stay in a meditative trance. There were plenty of times I stayed hidden while getting raided and players ran through my para and poison fields using magic trap pouches or the newer trapped crates, as they ran through my fields I remained hidden or was meditating while my guild members pushed the other players back.
