What is the “off” position for on ignition cylinder?

[SaharaBound]

I am replacing my cylinder this week because I can’t turn it to Acc and my key (including spares) are getting stuck. I never really thought of this until now but what is the ”off“ position for? When I turn it to that the key is stuck in and everything is off. 98 auto

 

[Vinman]

Flat towing. Keeping the key in the “off” position allows the steering wheel to turn freely without draining the battery