This post is part of our Boring series, where one Tuesdays we sometimes post analyses on signs we did not find particularly interesting. The idea is to offset personal biases.
The sign here is the capital "H" letter on a MacBook keyboard. It is indexing a place to press for the letter "H". Though we note that while "H" is a pretty literal icon for "H", most of the time pressing that key produces the lowercase letter "h". So the capital "H", while an icon for "H", also works as a symbol for "h" (and any other actions that might happen in a given context by "pressing H".)