USE        <skill>  [arguments...]              time: varies    priority: 3

Make use of a skill or spell that the character knows. Sub-skills usually have a function which is invoked through use. These actions are described in the lore sheets revealed when sub-skills are learned.

Category skills do not have direct use functions. For example, one could use the Sailing [601] skill to sail a ship:

use 601 west

But no use function exists for the category skill, Shipcraft [600].