We just always mark it get to the host aware, I only select milk and eggs when I book because we don't eat those. We don't select it for all restaurants just the ones we know the conversation needs to be started before we are seated. Many restaurants now are pretty good with vegan diets and don't need it, but it is helpful to let them know before because we have encountered many CM's who don't know what vegan actually means. Not saying you have to mark it as an allergy but it has been helpful to us in the past.