Mario,
according to the updated Code Recipes page, changing collections requires the use of an actions object. Would it not make sense to rename this parameter to tasks for the sake of consistency with the attributes and metadata endpoints?
I remember that the parameter was also named actions for attributes first while it was called tasks for metadata, and you changed it afterwards to streamline the API. Maybe this would make sense for the collections endpoints, too?
What do you think?
I have pondered this as well. Not sure if this will break too much... I doubt it. Probably I will change it.
I've changed it for the next release.