Probably the best of the OCO buttons because of its relative subtlety. She also did one (Button 975) for Alan Ackerman, too, for the VM Measurement Facility White paper, which I presented at the Winter SHARE in 1988 (easy for Alan to remember - his daughter Esther was born 1/1/1988). A lot of information about these buttons is on the VMSHARE archive - MEMO BUTTON and MEMO BUTTONxx (xx=SHARE conference number.). See http://pucc.princeton.edu/~vmshare/.