Official returns give "Present for Duty" and a somewhat larger "Aggregate Present" number. Makes sense -- sick call and the like.
However, Pemberton's returns for his "Cavalry Corps" in North Mississippi, December 1862 gives:
Present for Duty:
Officers: 246
Men: 8,607
Aggregate Present:
4,432
What's up with that? How do you have more present for duty than present? (Volume 17, Part 2, page 814)
Welcome to the byzantine world of Confederate record keeping. I am not sure that anybody to this day has ever been able to decipher what CSA returns actually meant. Even the Confederate army couldn't agree on what the numbers meant. Joe Johnston & Richmond went back & forth squabbling about how many men he actually had in the ranks. Confederate cavalry, in particular, produced almost clownish returns. It didn't help that he had the clown king of bizarre record keepers in his army.
Joe Wheeler's returns were always absurdly out of whack. At one point he reported nearly 20,000 of cavalry that an I.G. reduced to about 10 percent actually ready to ride into battle. Connelly, in
Army of the Heartland goes into detail about this issue. Here is an example from page 384.
"Due to a shortage of horses, Wheeler, on May 1, could muster only 2,19 effectives though some 8,062 were reported as present for duty... Though Wheeler could list only 2, 419 men as effectives, there were 18,785 cavalry allegedly on his rolls."
Official Records, XXXVIII. Pt.3 p. 676
Take you pick, 2,19; 8,062; or 18,785 are all correct numbers. Wheeler's returns were over 16,000 men & horses different depending on what roll you want to refer to. Is it any wonder that historians tear their hair out trying to make sense of this kind of thing?
The accounting can be broken down this way:
Aggregate means how many rations are you drawing.
Present means how many individuals including farriers, cooks, clerks, were on hand.
Effective means a healthy man fully equipped & astride a healthy, fully equipped horse.