-PARAMS is a base64-encoded Storable string containing the POSTed data as
-a hash ref. It normally contains at least one field, "uploaded files",
-generated by /elements/file-upload.html and containing the list of uploaded
-files. Currently only supports a single file named "file".
+PARAMS is a hashref (or base64-encoded Storable hashref) containing the
+POSTed data. It must contain the field "uploaded files", generated by
+/elements/file-upload.html and containing the list of uploaded files.
+Currently only supports a single file named "file".