U+20DD "⃝" Combining Enclosing Circle Unicode Character

U+20DD "⃝" Combining Enclosing Circle is a combining diacritical mark that is placed around a preceding base character to visually encircle it, rather than appearing as a standalone symbol. It is commonly used in mathematical notation to denote a circled operator, such as a circled plus or a circled times, or in pedagogical contexts to highlight or indicate a specific element within text. As a combining character, it relies on the character immediately before it for proper placement and rendering, and its appearance may vary depending on the font and application being used.