really stupid question.

[the_big_m_in_ok]

Hi Lee,

Jean L Naudin has been using fractions for wire diameters for decades now. See here for instance:
http://jnaudin.free.fr/2SGen/indexen.htm 

Maybe the French use it, Germans and others may be not, it is more common to use 0.5 or  .5  formats.

@gyulasun
Good to hear from you.
       I did see reference to the wire diameter wording in jnaudin's site above.   Interesting.   Whether or not he's alone in writing wire diameter descriptions that way is open to question.   Others in his country may take exception to his wording if they were really unfamiliar with it.   Those who research both European and American wiring schematics would immediately see significant differences in component identification symbols.   Capacitors are an obvious example to me.

--Lee