I'm not sure how to phrase this question, so, here's the concept:
Years ago, I went to a hotel and the waiters carried a stack of colored cards as a means to remember how many of each main a guest ordered. E.g. pink cards for chicken, blue for prime rib, green for veggie plate, etc.
When he went to each of his tables asking who wanted what, he would take the appropriate colored card from the main stack and put them in his hand. After collecting all the order from that table, he would put the pile of cards in some pocket (say right was table 20, left was table 21, etc.)
Is separating the cards into colors an act of "borer"? Or is this fine because he is using them as a means to serve people immediately? (I understand that separating items for immediate use is generally fine. However, here, he is using cards as a memory device to do something else, so he's not using the cards themselves, directly.)