Comment 3 for bug 988870

I have found the following:

The Atlantean coal mine says:
return=skipped when economy needs bread and not economy needs coal
return=skipped when economy needs smoked_fish and not economy needs coal

In the Barbarian micro-brewery's conf file is written:
return=skipped unless economy needs beer or workers need experience

It is parsed as "skipped unless (economy needs beer or workers need experence), so beer is produced if the economy needs beer of if the workers need experience.

So: Several return lines are possible. But it can also be written in one line, which should work too. (At least I hope I got it right.)