There's no international standard that I'm aware of. In fact, I think it would depend on the country-specific circumstances.
Tim O'Neill did a review of the Department of Finance's forecasting practices about two years ago. In that report there was an estimate done for Mr. O'Neill by the University of Toronto that to provide an assurance of staying out of deficit, in each and every year one would need to target a surplus in the order of $6 billion to $10 billion.