About this character
The official Unicode name is PLACE OF INTEREST SIGN — a name almost no one recognises. Everyone who has touched a Mac in the last forty years knows it as the Command-key glyph: ⌘. The looped-square shape is much older than the Mac, though. It is a Bronze Age pattern that survives on rune stones in Scandinavia and as the Sankt Hans cross in Finnish folk art. In modern Sweden and Finland it is used by the national heritage boards to mark a place of cultural interest on a map — the "place of interest" the Unicode name refers to.
The story of its arrival on the Macintosh keyboard is well documented. In 1983, when Steve Jobs was reviewing menu mock-ups for the original Mac, he objected to having the Apple logo appear next to every menu shortcut: too many Apples, he said, would cheapen the brand. Bitmap artist Susan Kare leafed through a symbol dictionary, picked the looped square because it was visually distinctive and culturally neutral, and the Command key has used it ever since. The Unicode Consortium assigned U+2318 in version 1.1 (1993) drawing on the symbol's existing typographic use.
U+2318 appears in keyboard documentation, in keyboard-shortcut hints in menus on macOS and iOS, and increasingly in cross-platform documentation as a compact way to say "Command". It has no HTML named entity. The character is a useful test case for fonts: it appears in most modern system fonts but is absent from some older or specialist faces, in which case browsers fall back to a tofu box. Other macOS modifier-key glyphs are U+2325 ⌥ OPTION KEY, U+2303 ⌃ UP ARROWHEAD (Control), U+21E7 ⇧ UPWARDS WHITE ARROW (Shift), and U+238B ⎋ BROKEN CIRCLE WITH NORTHWEST ARROW (Escape).