(I'm asking this question on behalf of a friend.)
My friend wants to go travelling around Europe and she has a Singaporean passport. Now, Singaporean passport holders don't need a Schengen visa in advance (as far as I know) as long as their stay is less than 90 days. However, she also wanted to work during the trip (teaching / bartending, etc) to support herself during the trip. Is that allowed, or does it require a working holiday visa? If it does require a working holiday visa, is there a common one that (like the standard Schengen tourist/business visa) or must one be obtained individually from each country in the itinerary?