A venue has an exclusive caterer (in Italian, catering in esclusiva) when it has an in-house caterer, or a single fixed supplier, and does not allow others. It is common at villas and estates built for receptions, but also at many conference centres.
For you it changes the order of choices: you choose the caterer when you choose the venue, and the tasting becomes part of the visit. The price is often a per-person package that may include spaces, menu, staff and basic set-up. The advantage is well-tested logistics; the limit is that you do not choose the supplier, and wine, cake or confettata brought from outside may come with restrictions or costs.
What to ask
Before you get attached to a caterer, ask the venue whether it has an exclusive arrangement. Then get in writing what the package contains, what is extra and whether you can bring a cake, wine or a certified kosher menu. The comparison with outside catering is in the guide on venues with exclusive or open catering.
