Do you mean to get the last x number of rows EXCEPT the last one where you don’t know the index/id/key of the last one? Only way I can think of doing it would be to sub-query it
This example is using the sample fiddle on SQLFiddle with a couple records added to the recordset
SELECT a.id
, a.rev
, a.content
FROM `docs` a
WHERE a.id < (SELECT MAX(id) FROM docs)
ORDER BY a.id desc
LIMIT 5