Dash Dash The dash is a punctuation mark that is similar in appearance to and , but differs from these symbols in both length and height. The most common versions of the dash are the en dash (–), equal to half the height of the font; the em dash (—), twice as long as the en dash; and the horizontal bar (―), whose length varies across typefaces. Historically, the names of en dash and em dash were loosely related to the width of a lower-case "n" and upper-case "M", respectively, in commonly used typefaces. Usage varies both within English and in
Chatham House Rule so that better international relations may be achieved. The rule is now used internationally as an aid to free discussion. The original rule of 1927 was refined in October 1992 and again in 2002. Chatham House has translated the rule into Arabic, Chinese, French, German, Portuguese, Spanish and Russian. The rule is a contrast (or a compromise) between private meetings, where revealing what was said in the meeting is forbidden, and "on the record" events where the discussion is completely public and attributed. Generally, the Chatham House Rule is imposed as a condition of being allowed to attend a meeting