What does "Delta" Mean?

[Raveshaper]

I have beat my head against the wall until I've gone through the other side on this one. I beseech thee, o greater users than myself. You are my last hope!

Upon looking into the Additional Remote Overrides menu, I discovered that according to the big list of Reason Remotables that "Record Enable Parameter Automation" is dependent on the selected track "Delta", which is determined by a delta value in MIDI.

What range of values does this accept? Is it linear, whereby 1 goes down a track and -1 goes up a track; or is it nonlinear, whereby a valid track "index" can be directly accessed numerically?

Does gaining focus of sequencer tracks using delta still work when master keyboard is turned off and input of notes is in separated mode?

[ScuzzyEye]

Delta "Δ" means change, or amount of change.

Additional: So I would guess that it means selecting a track relative to the active one. Range is probably ±127, like most things in MIDI.

[Raveshaper]

I know the mathematical definition, just not the midi implementation.