Orders and hidden units
 

I know from the manual that hidden units can perform some actions while remaining hidden. But what are they exactly? Or, to put it another way, what are the actions that will cause a stealthy unit to be visible?

Re: Orders and hidden units
 

In general, there's Hide (stay) and Sneak (move).

Spies get an additional command to instill unrest when in enemy territory. Assassins get an additional command to attempt to assassinate a commander. Succubi get a command which allows them to try to seduce a living male size-2 or size-3 commander. One Demon Lord gets a similar option but that can corrupt other commander types (restrictions not known; presumably not pretender, maybe nothing mindless?).

The other commands, like researching, defending, patrolling, building, et al are non-stealthy.

Re: Orders and hidden units
 

Preaching is also stealthy.