text: The card came to be known as the jack during the middle of the 19th century, when card manufacturers began to label playing cards to indicate their value with 2, 3, 4, 5, 6, 7, 8, 9, 10, J, Q, K, A. The obvious confusion between "Kn" and "K" led to the renaming of the knave, being out-ranked by the king.