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
Two-second rule is suggested that drivers say "only a fool breaks the two-second rule". At a normal speaking rate, this sentence takes approximately two seconds to say and serves as a reminder to the driver of the importance of the rule itself. The TailGuardian distance advisory decals recently adopted by Stagecoach Buses in the UK use the two-second rule in their calibration. Advisory Decals for 30, 50 and 70 mph are calibrated to be invisible outside those safe distance, only rendering themselves visible once the car following has entered the safety zone for the speed that they are travelling. Some authorities regard