The hamburger

a trigram doing menu duty

Unicode: U+2630 trigram for heaven — the character usually pressed into service is ☰ qián, Heaven, from the Bagua
The job: Hide a list of destinations behind one small control, and signal that the list is there.
Standards: None. Norm Cox drew it for the Xerox Star in 1981, where it marked a list — an origin that is documented and rarely credited. It has no standards number, no registration, and no authority behind it beyond forty years of copying.
Failure modes: The **best-evidenced failure in this department**, because it is one of the few marks that has been A/B tested at scale: hiding navigation behind it consistently reduces discoverability and use against visible labels, and the standard remedy — putting the word Menu under it, or in place of it — measurably recovers the loss. A symbol that needs a caption to work is a symbol that has failed, and this one is deployed on a large fraction of the web anyway.
Cultural flips: The name is pure Western food imagery and does not travel; the mark itself is read as a list almost everywhere, which is what it is. The Institute notes without comment that the character most often used to typeset it is ☰, Heaven, the first trigram of the Bagua (→ Systems) — a cosmological figure conscripted as a button.

Sources · 3

documented Norm Cox’s design of the icon for the Xerox Star, 1981.
documented The Unicode Standard, U+2630 TRIGRAM FOR HEAVEN — its actual identity.
traditional The discoverability findings. Widely reported across independent tests, and not consolidated into a single citable study, so the Institute reports the direction rather than a figure.