I am just starting to use RAML.
Most Web toolkits such as the servlet API in Java provide a list of parameter values for handling repeated parameters of the same name. It seems to be a cleaner approach than inventing a sub-syntax inside of a query parameter to have a list. Instead, you introduce each repeatable parameter value with the name of the query parameter, i.e.
This has three different filters that may apply to the file extension, which is intermingled with other single parameters.
I have seen nowhere that it is forbidden or permitted to repeat parameters in a RAML URL, so I assume it is permitted. I do not want to have to invent list sub-syntaxes that get escaped in their own way.
But I would have expected to see an additional property of query parameters, like required, but called something like "repeatable", so we distinguish whether a parameter may be repeated. If required is important, then repeatable should be as well.