Spacing, or designing the spaces inside and between letters, is the oft overlooked supremely important aspect of designing type. Though this is popular opinion among the most legit of pros, it can be counter-intuitive (get it?) for anyone new to type design.
When spacing a typeface, the lowercase n is a logical place to start, due to the fact that it has two vertical (or nearly so) stems, and space between them. Similarly, the o will define the space around curved strokes, which is another very important decision to make. In the capitals, the H has those vertical stems with space between, and the O will define the spacing on capital round strokes.
For those reasons, H, O, n, and o are incredibly influential letters when it comes to spacing, and supplying the overall genetic material for a typeface. I was looking for what word or words could be made with those letters, and I stumbled on “OH no.” The name is a reference to proper spacing, and respect for the craft.
It’s also like, “Oh nooooo!!!!!”