Tyrwhitt's economical rules of engagement

Tyrwhitt's memorandum gives commanding officers discretion to retaliate when British ships are fired upon and to act immediately when British lives are endangered. It demands the smallest practical expenditure of ammunition and resources because ineffective firing is politically and economically damaging. Wasteful gunfire also weakens the moral effect of naval retaliation and may encourage further attacks. The warning invokes the battlecruisers at Dogger Bank as an embarrassing example of the kind of firing to avoid. Officers are therefore to fire only at definitely located targets that their available weapons can affect. When effective retaliation is impossible, they must report the culprit's position, the circumstances, and the force required for a punitive response, preserving local initiative inside clear limits.