I'm always confused when I see people report a "rule" about honesty. It seems contradictory.
If you've established a mutual desire for honesty, then a rule about it is superfluous. However, if you've found yourself in a situation where honesty is not mutually respected, then implementing a rule will only produce more opportunities for honesty to be violated.
“As I am sure any cat owner will be able to tell you,
someone else putting you in a box is entirely different
from getting into a box yourself.” —bisexualbaker