How to prevent players from gaining hidden info?

Any way to prevent players from using something like @{target|armor_class}?

There really isn't unless the token isn't actually linked to a sheet.  If it is visible to the players, they can use target macros like that if they know the attributes to look for.  I would say to keep enemies on the GM layer until encountered.  Once they are encountered, they will end up figuring out the AC soon enough anyway if it comes to combat.

You know what, disregard my earlier statement. I found a slight way you can. But you'd wanna make sure to keep the NPC sheet open while doing so. 1st: check out the Invisible Token  rig and upload into said game. 2nd: drag and drop said token into area with NPCs. 3rd: right click your Invisible token and go to Advance>Bring to Front. 4th: Over Lap Invisible token with NPC, and click/drag multi select both tokens. 5th: Right click Group Now when I go to move the Token, it still shows the npc, but when I use target|ac  or what ever the actual code is for any said game, it'll show up blank since the Target selected was actually the Invisible token! Just do some trial and errors with Moving your NPC now as a grouped item. I found Clicking it, waiting without holding down the clicker, and then dragging to said future spot, kept the tokens over lapping instead of doing the Glitch Spread stuff. Hope it helps!! oh and to recap, keeping the invisible token over the npc will void all your click macros per selected/targets for npcs, that's why youd wanna keep their sheet open ahead of time to do their attacks and such.