What is the official name of the yellow McDonald's logo elements?

The yellow McDonald's logo elements are officially known as the Golden Arches.

The arches originated as architectural features on McDonald's restaurant buildings in the 1950s. Architect Stanley Clark Meston designed the original arches for the San Bernardino restaurant concept, and the shape later became an independent corporate symbol rather than merely part of a building.

In 1962, Jim Schindler combined the two arches into the familiar “M” logo. That logo helped make the arches instantly identifiable even when a complete restaurant was not visible.

“Golden Arches” is the established name for the symbol. The phrase is not the same as the company's informal “Golden M” description, and it does not refer to a particular menu item or mascot.