I think it was what you meant, but just to clarify: onsite guests can book 180 days out from their check in date and then book for the next ten days of their trip, so will just have to go to the website or make one phone call at 180 days out from their check in date. Offsite guests can book at 180 days out too, but must call (or go online) every day at the 180 day mark of the day they want to make ADRs for.
People staying onsite don't get to book 190 days out from their check in date, they just get to book all their ADRs for their trip at one time at the 180 day mark and don't have to call back every day (or go online every day) like people staying offsite would.
In other words if person A was staying onsite and checking in Sept 1st, then they could call 03/05 (180 days out from Sept 1st) and book ADRs for Sept 1st-10th and be done with it. If person B was staying offsite and also checking in Sept 1st, they could also call 03/05 (which is also 180 days out from their Sept 1st arrival date) and book an ADR for Sept 1st only, then they'd have to call back the next day to book an ADR for Sept 2nd, then call the next day to book an ADR for Sept 3rd, and so on.
For some reason some people think that if you stay onsite it gives you the benefit of being able to make ADRs 190 days out from your check in date. That's not true. It gives you the benefit of making all your ADRs 180 days out for days 1-10 of your trip. Offsite guests still get to make ADRs at 180 days out too, but only for the date is that is 180 days out. They must call or go online each day for subsequent days. The benefit for onsite guests is that they might be able to get an ADR at their 189 mark for a restaurant that is very hard to get and that ADR might not be available nine days later when an offsite guest would be eligible to try for it. Neither onsite, nor offsite guests can book ADRs before the 180 day mark though.