The small projecting feature (a foot, slab, or wedge) at the end of a Stroke in a Serif Typeface. In the anatomical sense (as distinct from the classification sense), a serif is a discrete structural element whose form, size, and attachment style vary widely across subgroups: Old Style Serif serifs are typically bracketed with a smooth curved transition into the Stem; Slab Serif are thick and block-like with minimal or no bracketing; Modern Serif serifs are unbracketed hairlines. Serif shape is one of the quickest visual cues for identifying a typeface's classification.