<P> The slashed zero long predates computers, and is known to have been used in the twelfth and thirteenth centuries . It is used in many Baudot teleprinter applications, specifically the keytop and typepallet that combines "P" and slashed zero . Additionally, the slashed zero is used in many ASCII graphic sets descended from the default typewheel on the Teletype Model 33 . </P> <P> The slashed zero is used in a number of fields in order to avoid confusion with the letter' O' . It is used by computer programmers, in recording amateur radio call signs and in military radio, as logs of such contacts tend to contain both letters and numerals . </P> <P> The slashed zero, sometimes called communications zero, was used on teleprinter circuits for weather applications . </P> <P> The slashed zero can be used in stoichiometry to avoid confusion with the symbol for oxygen (capital O). </P>

Do you put a line through a zero or an o