Drivers can ignore invalid signs and never be charged for ignoring them.
Under s. 10 of the sign regulation, when all approaches to an intersection are controlled by stop signs, an All-Way tab sign may be appended to the stop signs directly below them.
http://www.e-laws.gov.on.ca/html/regs/e ... 0615_e.htm
Because the word "may" is used (and not the word shall) it is not imperative that the All-Way tab be added to stop signs.
However, when a city elects to add the All-Way tab, and the city is governed by the French Language Services Act (FLSA), but fails to add the bilingual ALL-Way tab, and only uses the English All-Way tab, in violation of the FLSA, do you think the entire stop sign becomes an invalid stop sign?