Arty overload point margins

[Weasel]

I have been wondering about this, finally found it on shrapnel; good to know:

In an assault your artillery points spend is unlimited. The advancing side in an advance/delay can have 30% of his points as artillery before overload applies. In a meeting engagement, both sides are allowed 20% of total points as artillery. All others are limited to 15% of total points to be spent on artillery before overload penalty.

If you go over those limits your opponent will be awarded penalty points at game end.