This observation was reported once and cannot be considered a regular occurrence.

Similar cases became almost a regular occurrence during the years of occupation.

I mean, if it had been a regular occurrence I'd have said something for certain.

Maybe they would have to make this a regular occurrence.

At the same time, haze has been a regular occurrence.

He asked them if that was a regular occurrence, too, and again they said no.

This was a regular occurrence for the entire run of the series.

The inclusion of foreign countries did not become a regular occurrence, however.

"Most people are embarrassed by the fact that this seems to be a regular occurrence."

Of course, games weren't cheap either so this wasn't a regular occurrence.