Bar (diacritic)
A bar or stroke is a modification consisting of a line drawn through a grapheme. It may be used as a diacritic to derive new letters from old ones, or simply as an addition to make a grapheme more distinct from others. It can take the form of a vertical bar, slash, or crossbar.
A stroke is sometimes drawn through the numerals 7 and 0, to make them more distinguishable from the number 1 and the letter O, respectively.
In medieval English scribal abbreviations, a stroke or bar was used to indicate abbreviation. For example, the pound sign, is , with a cross bar.
For the specific usages of various letters with bars and strokes, see their individual articles.