Reported by @MartinPoulter on the glamtools mailing list

There are different ways a template can be specified: by its name (e.g. cc-by-sa-4.0 ), by wiki markup ( {{cc-by-sa-4.0}} ), by its name with namespace ( Template:Cc-by-sa-4.0 ) or by a web URL ( https://commons.wikimedia.org/wiki/Template:Cc-by-sa-4.0 ). When I put a template in the form, it's not always clear which of these formats to use, and in fact the answer is different for different fields. With a bit of experimentation it becomes clear, so it's not a severe problem, but it would be easier if the form was more clear about which format to enter.
For the License template field, the form gives an example of {{Template:Cc-by-sa-3.0}}, but the Template: namespace is unnecessary.