There is some scope for confusion when an overline is meant to denote multiples of 1,000, and when not. The Greeks and Romans often overlined letters acting as numerals to highlight them from the general body of the text, without any numerical significance. This stylistic convention was, for example, also in use in the inscriptions of the Antonine Wall, and the reader is required to decipher the intended meaning of the overline from the context. The "vinculum" for marking 1,000s continued in use in the Middle Ages, though it became known more commonly as "titulus".