Control Points, Gap and Kerning
"Some of the letters in my font overlap each other when I use it in mySewnet™ Embroidery."
Control points are the points you place to digitize an object. For example, Single Stitches have two control points (one at each end), and Satin Columns have as many points as you placed when constructing the column.
The gap (or tracking) between characters is a standard distance between each character, measured using the control points. Occasionally, characters might overlap because there are not enough control points.
Similarly, automatic kerning is used in mySewnet™ Embroidery to improve the appearance of text by moving certain pairs of characters closer together. There must be enough control points to ensure that the character pairs do not overlap each other.
Such issues may be found in a very plain font using only a few satin columns or very simple fill areas. Ensure there are plenty of control points by putting down underlay stitches first. Alternatively, if using a specialty fill with a border, insert extra points into the outline of your characters.
Use Insert Points on Straight Lines 
to add extra points automatically to a straight border line for a fill area or column. Use Insert Points 
to add points to a line by hand. See Insert Points on Straight Lines.