Formality, noun: an established form or procedure that is required or conventional.
We first read this word in The Hunger Artist by Franz Kafka. Its used in reference to an unnecessary action that is performed at each of the artists productions, which in this case was a volunteer making sure that the artist was not sneaking food.
“Apart from the changing groups of spectators there were also constant observers chosen by the public—strangely enough they were usually butchers—who, always three at a time, were given the task of observing the hunger artist day and night, so that he didn’t get something to eat in some secret manner. It was, however, merely a formality, introduced to reassure the masses, for those who understood knew well enough that during the period of fasting the hunger artist would never, under any circumstances, have eaten the slightest thing, not even if compelled by force. The honour of his art forbade it.”