What's the character code for exclamation mark in circle?

Question

What's the Unicode or Segoe UI Symbols (or other font) code for exclamation mark in circle?

Solution

There is no single Unicode codepoint for that particular symbol.

Unicode does define a U+20DD COMBINING ENCLOSING CIRCLE codepoint, but most fonts (including Segoe) do not treat it as a combining symbol, but rather as its own character. In Word, for instance, you would have to adjust the character spacing between it and a preceding character (in this case U+0021 EXCLAMATION MARK) to a negative offset to make them overlap (see Using the “Combining Enclosing Circle” character in Word).

Some fonts do support U+20DD in general (see COMBINING ENCLOSING CIRCLE (U+20DD) Font Support), and some of them do treat it as a combining mark (Code2000, GNU FreeFont fonts, STIX fonts, Symbola, XITS, etc), but the resulting overlap may not visually be exactly what you are looking for, depending on the size and alignment of the character it is being combined with.