Filled by LIST_DRAWN every turn: record numbers, then $FF. While SORT_AND_DRAW works through the list it sets bit 7 of each entry as that object is drawn, so the list also says what is still to do; RENDER_DYNAMIC_OBJECTS reads it first to wipe what moved. All zero on the tape.

64 bytes: room for all 56 records and the $FF, with seven to spare. Pentagram's list, 48 bytes for 54 records, can overflow into the code after it; this one cannot. Measured in the simulator over the build's room tour (every room in turn, a few seconds of walking in each): the longest list was 51, first reached around room $74.