Custom limits on wifi

[szatox]

It's a low priority thing, but I might be interesting to explore.
Say, I have a machine running hostapd with crda.
Crda is used to set runtime limits like channels available and max TX power. It seems to also be used to instruct the clients how to behave, though I don't know how exactly that information is passed on.

Now, I only need wireless access in a very small area. There is no need for the signal to cover the area within 100m radius, or penetrate walls. I could probably limit it to 1mW and still have all my needs covered, at the same time limiting the leaks to the "environment".
This can be easily done manually on one end of the link, but the clients may or may not be smart enough to limit their power output depending on the link quality. So... Can I abuse crda or (something else) to have the access point inform the clients that local regulations don't allow them to do certain things (like transmit strong signal)

[Logicien]

The Linux module cfg80211 allow to set the regdomain and to activate or desactivate the 40Mhz channel width in the 2.4mhz bandwidth.