No planet bombardment treaty

[Q]

I found it out the hard way:
If you ever agree to a treaty with "no planet bombardment" allowed for your empire, don't attack enemy colonies!
My ship moved toward the colony but refused to fire and got slaughtered by the weapon platforms from the planet.

And it is so easy to miss this treaty element if you don't control very carefully the proposed treaty.

You can however land troops on the planet, if your troop transporter survives the fire of the weapon platforms.