▁marry . ▁ ▁Origin ▁and ▁development ▁▁ ▁This ▁ancient ▁custom ▁is ▁similar ▁to ▁the ▁publication ▁of ▁b ann s ▁of ▁marriage , ▁but ▁it ▁is ▁a ▁civil ▁process ▁not ▁an ▁ecc les iast ical ▁one . ▁( O nder tr ouw ▁does ▁not ▁refer ▁to ▁the ▁b ann s . ▁The ▁Dutch ▁phrase ▁for ▁" b ann s " ▁is ▁k erk elijke ▁h uw elij ks a ank ond ig ing .) ▁O nder tr ouw ▁existed ▁before ▁the ▁Re formation ▁and ▁was ▁continued ▁afterwards . ▁O nder tr ouw ▁has ▁surv ived ▁into ▁modern ▁times ▁and ▁exists ▁today ▁as ▁a ▁pre - mar riage ▁legal ▁requirement ▁in ▁both ▁the ▁Netherlands ▁and ▁Belg ium . ▁In ▁both ▁countries ▁civil ▁marriage ▁is ▁comp uls ory ▁and ▁cou ples ▁int ending ▁to ▁marry ▁register ▁the ▁onder tr ouw ▁before hand ▁at ▁the ▁civil ▁registry ▁( B urger lijke ▁Stand ). ▁O nder tr ouw ▁is ▁now ▁analog ous ▁to ▁the ▁process ▁of ▁applying ▁for ▁a ▁marriage ▁lic ence . ▁Sometimes ▁it ▁is ▁referred ▁to ▁as ▁notice ▁of ▁intention ▁to ▁marry ▁( hu w elij ks a ang if te ). ▁ ▁O nder tr ouw ▁should ▁not ▁be ▁confused ▁with ▁the ▁reading ▁of ▁the ▁b ann s , ▁eng agement ▁or ▁bet ro th al . ▁The ▁word ▁onder tr ouw ▁itself ▁has ▁no ▁English ▁equivalent . ▁A ▁common ▁phrase ▁used ▁in ▁this ▁context ▁is ▁" in ▁onder tr ouw ▁ga an ". ▁A ▁similar ▁phrase ▁used ▁in ▁the ▁ 1 8 th ▁century