GNU Emacs Lisp Reference Manual

29.8.1: Kill Ring Concepts

The kill ring records killed text as strings in a list, most recent first. A short kill ring, for example, might look like this:

("some text" "a different piece of text" "even older text")

When the list reaches kill-ring-max entries in length, adding a new entry automatically deletes the last entry.

When kill commands are interwoven with other commands, each kill command makes a new entry in the kill ring. Multiple kill commands in succession build up a single entry in the kill ring, which would be yanked as a unit; the second and subsequent consecutive kill commands add text to the entry made by the first one.

For yanking, one entry in the kill ring is designated the ``front'' of the ring. Some yank commands ``rotate'' the ring by designating a different element as the ``front.'' But this virtual rotation doesn't change the list itself---the most recent entry always comes first in the list.