I don't know where you're getting that. While on the "M" screen, I type an "h". This brings up the help menu with "Current Screen Metrics" already highlighted. Since my selection is highlighted, I just press return. I am now at the "Process Memory Regions" menu. I use my downarrow key to scroll down to "RSS" and I press return:
Quote:
The size (in KBs unless otherwise indicated) of the resident memory occupied by the memory region.