6.2 General Punctuation (PDF), in The Unicode Standard, Version 11.0.0, Mountain View, CA, The Unicode Consortium, 2018, p. 273, ISBN 978-1-936213-19-1. URL consultato il 12 dicembre 2018.
«Spacing Overscores and Underscores. U+203E OVERLINE is the above-the-line counterpart to U+005F low line. It is a spacing character, not to be confused with U+0305 COMBINING OVERLINE. As with all overscores and underscores, a sequence of these characters should connect in an unbroken line. The overscoring characters also must be distinguished from U+0304 COMBINING MACRON, which does not connect horizontally in this way.»
