Able to limit reservation suplements could be important feature on some reservations.

Example:
Somebody is renting places for motorcaravans with and without electricity.

Booking process is more complex for customer if there are non-electricity and electricity reservation items instead of one item with option to select non-electricity and electricity (or whatever there are defined on suplements list).

Hello, I'm not sure what sense has your request exactly. You can create two reservation types with different prices: place with electricity and place without electricity. Or paid supplement of type yes/no. I don't know what do you mean with limited supplements. Could you describe it in more details?

Two (or more) reservation types with exact same price and reservation conditions but with different suplements are too slow to maintain because each price update have to do twice on both reservation types. That is also against database normalization because same data is saved many times in database.

Example:
If i am renting places for motorcaravans with and without electricity. I have 20 places for motorcaravans but only 10 of them are with electricity.
I can't use single reservation type with "yes/no" selection on electricity because i found myself on situation someday that every places are rented with electricity but only 10 of those are able to get it.

Hello

I understand. You have one object with capacity 20. But only 10 of them have electricity. Current version hasn't limit for supplement. We can do it for you as paid customisation or you can create two objects. One with electricity and capacity 10. Second without electricity and capacity 10.