When you create the custom field for the passport date, you could set the Earliest Possible Date setting to be within 6 months of the meeting travel time. That way if someone enters a date within 6 months of their expiry it would give them an error message. You could even use Language Management to edit exactly what the error message says.I think the best way to get around your admission item issue is to remove that page from your registration altogether. As long as you only have the one admission item setup, with the same fee for anyone purchasing it, you don't need to have that page. As they go through registration, that admission item will automatically be assigned by default. Instead, at the top of your agenda page, you could drop in a text box that says something about the package/price and what is included. The admission items will show up on the summary page too so you could also edit how that displays so that the registrant gets all the information they need in that area too. Hope this helps!