There is a trail pointer which selects some entry of the trail at any given time. The following commands operate on the trail pointer in various ways. It allows you to re-use any previously computed value without retyping. With a numeric prefix argument n , it yanks the value n lines above the current trail pointer. All of these commands accept numeric prefix arguments to move several lines or screenfuls at a time.
Trail markers are useful mainly as the targets for later incremental searches in the trail.
The line is saved in the Emacs kill ring suitable for yanking into another buffer, but it is not easy to yank the text back into the trail buffer. With a numeric prefix argument, this command kills the n lines below or above the selected one. The t . It prevents that command from removing its arguments from the stack. This works for all commands that take arguments off the stack.