They somewhat follow the OP's definition of sigil (in the yellow box), which doesn't say that sigils have to be interpreted in a special way, only that they con

They somewhat follow the OP's definition of sigil (in the yellow box), which doesn't say that sigils have to be interpreted in a special way, only that they convey some meaning to the programmer (although it's a bit unclear - communicate to whom, programmer or interpreter?). They are also not at the beginning of the word, but that seems to be rather arbitrary requirement.