A more thorough explanation:

ferdfare

Ferdfare is an old English word that means a summons to military service or an exemption from military service. It comes from the Saxon words "fird" which means "military service" and "fare" which means "a going".

• When the king needed soldiers for his army, he sent out a ferdfare to all the able-bodied men in the kingdom.
• Some people were granted ferdfare because they were too old or sick to fight in the war.

The first example shows how ferdfare was used to call people to military service. The second example shows how ferdfare was used to exempt people from military service.