notation - Proper use of the vinculum to indicate repeating decimal.

A nerdy debate with a colleague leads me to ask this question:

To be used correctly, does the vinculum HAVE to only be placed over the shortest sequence of digits that repeat after a decimal?

For example, to indicate 1/3, is it ok to write $0.\overline{33}$ instead of $0.\overline{3}$?

Thank you!