"Brown explained that the Greek word gnomon (“one that knows or examines”) is used to refer the pin or rod of a sundial, the part whose shadow falls upon the dial to tell an observer what time of day it is. For Brown, marks of punctuation were knowing gnomons too — “index marks”, as he described them, that pointed out something of interest in the surrounding words just like a shadow on a dial, and his new terminology was loaded with coincidence."