While in some cases the font doesn't necessary need to be monospaced, some documents might require that a monospaced font is used, so it should be monospaced an

While in some cases the font doesn't necessary need to be monospaced, some documents might require that a monospaced font is used, so it should be monospaced anyways. Although, as you say, different from the main copy; so if all of the text is monospaced, there should be some way to distinguish it, such as by selecting a different monospaced font, or displaying it with a different colour. (One case where a monospace font is required is if you are automatically including text from another document which uses plain text format; there is no way to determine what format is needed, but monospace will always work.)