Men must turn square corners when they deal with the government.

Explanation

(English-origin maxim.) Those who deal with the government must comply strictly with all conditions and requirements — equitable excuses for non-compliance that might work between private parties will not avail against the sovereign.

Where this applies

• A citizen files a tax return with minor errors and the government rejects it entirely.
• Someone dealing with the government fails to follow exact procedures and loses their case.