(integer) number indicating the maximum number of keys to
return (max 1000, default 1000).
marker
(character) string that pecifies the key to start with
when listing objects in a AWS bucket. Amazon S3 returns object keys in
alphabetical order, starting with key after the marker in order
prefix
(character) string that limits the response to keys
that begin with the specified prefix
delimiter
(character) string used to group keys. Read the AWS
doc for more detail.