Hi Hilary,
I've posted forum in another category as you suggested. (https://www.infopathdev.com/forums/p/39700/121991.aspx#121991)
i will try to elaborate my issue with considering example this blog. suppose, User enter this ("?Referrer=email” ) parameter already and now it's exist. and again i pass same parameter in URL that time i'm expecting error saying that "this item is already exist" but now its opening new form.
Thanks