Let's assume you want to create a style for headlines where the first letter will be slightly smaller than other letters, e.g. the first letter size is 94.5% of other letters size. After you've specified the font, the size and the leading, add following code to your tags:

>il H<>dropc 1,1,0,0<>h IL*945/1000<>il 0<

Explanation

Since the value of type size (H) gets changed after >dropc..<, we have to save it as it is here. We could to it with >sav< and restore it later by >res<, but >sav< saves and >res< restores too many things, some of them might collide with >dropc...< tag; thus, we chose to use a non-ortodox method to save only one value. Since there's a variable IL (which stores the left indent value), and since the left indent is not used in this headline (btw, it's used very seldomly whatsoever), so with >il H< we initialize the left indent variable to the value of the current type size.

We use dropc for 1 character only.

Specifying the >h..< tag after >dropc..< tag, it affects only the first letter. Since we know that original height is stored in IL, so we use >h IL*945/1000< in other words, applying 94.5% of height.

As a last thing, we reset the left indent to 0.