I believe this means men who were unattached to their units for some reason or small commands (smaller than a company maybe platoon size etc) who were thrown together without any previous command structure as a unit. I do know that Williams Casuals were made up of men from various units, 19th Ark Inf (Dockery's), 20th Ark Inf etc who were small units. I have seen reference to these. I know for a fact there were some of Crawford's cavalrymen who were wounded and fought at Jenkins Ferry most likely due to loss of horse during activities prior to the evacuation of Camden. Exactly who they served with is not mentioned or known. There were probably more. The cavalry was not there at Jenkin's Ferry other than those Missouri troopers who opened the show with retreating Feds from Guesses Creek to the Jiles farm.