The /jog command will have a different affect depending on which jog mode is selected. The jog system has two commands and gives feedback of the mode chosen.

/jog delta Where delta is a float indicating the ammount and direction.
/jog/mode mode Where mode is an int from 0 to 7 indicating the mode

Feedback is as below

/jog/mode/name name Where name is a string indicating the name of the current jog mode.
/jog/mode mode Where mode is an int from 0 to 7 indicating the current jog mode.

Jog Modes

The jog mode may be set using a slider with 0 to 7 limits, a group of switches or radio buttons. What works in any situation will depend on the controller.

Scrub

Scrub deserves special mention. In an ideal world, scrub would be jog with sound. However, Ardour does not have that functionallity yet. So scrub starts the transport rolling at either 50% or 100% depending on how fast the jog wheel is turned. The position of the last tick is always saved and if no more ticks are received, the transport is located there when stopped at time out. If the jog wheel gives a value of 0 when released the transport stops at the location the value 0 is sent.