How To Write A Leave Letter For Marriage . The principal, (school/ college name), (address/ city) date: I have one elder brother; How to create a leave letter for marriage? Download this leave letter from www.pinterest.com Use it to state the reason for your leave. Leave application of (your name) for (number of days) to attend an engagement party. As it is a leave application letter, the reason for which you are taking the leave should be explained in a clear way.