How do you use recommendations for multiple schools?

I'm not sure how the recommendation process works :

My list of schools : INSEAD(4th round), Columbia(1st round), WUSTL Olin DBA finance
My profile :
Ivy League(Dartmouth/Penn/Brown) economics major(with 8 courses in philosophy), GMAT 770, 4 years of experience in central bank
High evaluation marks at work, three authored research articles(one as first author)


Is it that you have one set of recommendations that you can send to multiple schools, with the exception of different formats that should be catered separately from the main set of recommendations(schools that require recommendations from different sources et cetera)

Are there recommendation formats and questionnaires that need to be followed? Where can I find these formats? Are these formats sufficiently different according to school so that you need to redo recommendations every time you write them?

Finally, for the DBA finance program that I'm also trying to apply to ; there are three recommendations needed; are they all from work or are some of them academic?



Thank you for your kind answers.