What does Recoup Percentage on Expense Mean?

Recoup percentage, in short, means the percentage of the expense that you wish to recover from the artist. Suppose that you as a label were charged an expense of $100 for Artist A. If you wished to recover all of the money from the artist, you would set the recoup percentage for that expense at 100%. If you want to recover half of that money, you would set the recoup percentage for that expense at 50%.