Happy with pretty basic salads but here's my list:
Ok to:
Lettuce
Tomatoes
Hard boiled egg
Salad cream
Beetroot (only a little, and not soused in vinegar, please!)
Celery (just a little - chopped, not whole stalks)
Crisps
Potato salad (if made with nice new potatoes)
Grated cheese
Feta cheese
Raw carrot
Fresh herbs

No to:
Olives
Spring onions
Other raw onions (bound to bring on IBS!)
Vinaigrette dressing
Anything in vinegar
Walnuts or other nuts - so forget your Waldorf!
Coleslaw of any type
Cucumber (burping it all day afterwards!)
Rocket - bitter ++

And with:
Chicken
Salmon
Tuna
Ham has to be just right: not fatty or stringy

Not keen on cold beef or lamb or anything "pulled"