Final answer:
Executioners in the 18th century wore black hoods to conceal their identities and separate their actions from their personal identities. This tactic is called anonymity.
Step-by-step explanation:
The tactic you are referring to is anonymity. Executioners in the 18th century wore black hoods in order to conceal their identities. By wearing these hoods, they could separate their actions from their personal identities and the morality associated with them. This allowed them to carry out their duties without being personally associated with the act of execution.