What can I substitute in a recipe for Brown mustard seeds?

Will the recipe be okay without it?

What can I substitute for dijon mustard in a recipe?

The recipe calls for 1 tbsp of dijon mustard. I don’t have any honey on hand.
i have regular mustard
the recipe is for pineapple chicken

I have an allergy to mustard/mustard seed. Is there any thing I can use for a substitute in recipes?

Is there a substitute for mustard that can be used in recipes calling for it?

I have a recipe for crushed brown mustard seed. Can I substitute “ground mustard” instead?

I couldn’t find “brown mustard seed” anywhere. Can I substitute ground mustard instead?

Is there something that can be used as a substitute for mustard or cumin in recipes?

I am allergic to mustard and cumin and leave them out of recipes when I cook. Since they are used to add flavor to a dish I am wondering if there is something that would be a good substitute for them when cooking to add flavor to the dish.