TomeNET

q       q       quaff a potion.
                If you enable the 'keep_bottle' option (it's in =0 at the time
                of writing this) your character will retain an empty bottle

                If n is omitted, the default value of 15 will be used.
                Use this mainly for empty bottles, especially in conjunction
                with the 'keep_bottle' option enabled, to prevent uncontrolled
                amassment of empty bottles. Example:  !K10

- To obtain water or salt water you can just fill up an empty bottle with
  sea water or freshwater at the appropriate terrain. To obtain empty bottles
  you can make use of the "/empty" command or the "keep_bottle" option in  =0 .