The letters i and j are often interchanged in both capital and small formation eg you may find justice spelt iustice and James spelt Iames. A j is often used in place of the last i in writing Roman numerals.
The other feature of the letter i is that it belongs to a group of letters made up by minims. A minim is a single short vertical stroke. The letter i is made up of a single minim, with or without a dot above it. Other letters made up of minims are m, n and u. The m is made up of three minims joined together, while n and u are made of two. Below is the word munition, demonstrating each of the letters made up by minims.
Some clerks used a tittle mark above the letter u to distingush it from the n. A tittle mark is a short horizontal line written above the letter. The following word is young, written with a tittle mark above the u.
Sometimes the line is not very straight and sometimes it is very short. Othertimes it may be slightly to one side or the other of the u, just as i can be dotted to the left or right.