Ukulele chord shapes are often notated on little grids.
They are usually no deeper than 6 frets, but by adding a fret number to the side of the top fret, they can be used to indicate chord positions anywhere up on the neck. This system saves space in manuals and other instructional materials.
However, as a ukulele student BUG member David Mayerovitch often wished to have a grid that is a closer reflection of the way the fretboard actually looks, and shows positions on the neck in relation to the uke's own fret markers. So he created a representation of a fretboard containing 13 frets, which should be enough for most practical purposes. He put the usual markers at frets 5, 7, 10 and 12. Putting two of these grids side by side to illustrate a chord change allows a uker to see the movement of the hand as well as the positions of the fingers. Different positions of the same chord can be noted on a single diagram. These grids take too much space to be useful in published material, but they're fine for a learner's personal notes.