Pack your own lunch, or at least bring some backup food. I've been to the conference centre twice for work.
The first time was a catered lunch. My meal was delivered to me on a separate plate with cellophane over it and my name. It was a sandwich with some salad. The bread crumbed the second you looked at it, but I know the struggle to find decent GF bread and can only imagine how hard that is at commercial scale.
Yesterday was an unmitigated disaster. They served some salads and build your own sandwiches, all buffet style. Nothing but the bread was labelled. The GF bread was in a separate basket. I skipped the sandwiches entirely due to all of the cross contamination and had some salad with no dressing.
— No gluten-free information on the menu
— Not Much/None
— Poor