Can dried mustard powder be left out of a recipe?

If there are other spices in a recipe, can you skip dried mustard powder? Will it mess the recipe up, or can this ingredient be skipped in a dire situation?
thanx!!!! i solved the problem!

What must I do to effectively remove dried Yellow Mustard from carpet?

Already I have tried friction-brushing it off….cold water…..cold water with dish washing liquid and brushing again….Part of it is gone….but not the sunny yellow color……I am hoping you can help me.