U+2981 "⦁" Z Notation Spot Unicode Character

U+2981 “⦁” Z Notation Spot is a small, filled circular symbol used primarily in formal methods, specifically within the Z notation, a formal specification language for software and systems engineering. In this context, the spot often serves as a marker or placeholder within mathematical expressions and set-based definitions, helping to denote a specific position or element in a structured way. Beyond its technical roots, the glyph appears in mathematical and symbolic notations where a compact visual focus point is needed, though its use remains niche compared to more common punctuation marks or geometric shapes.