Thread:Extension talk:Scribunto/'Equal' character used in template parameter messes things: bug or feature?/reply (4)

You can set the empty-string default when forwarding it to the #invoke (i.e. ), and then in Lua test for empty string to decide if it was given. Do the same thing for parameter 2,.

You could also use  to directly access the arguments passed to the template that contains the #invoke, without having to forward all the arguments to the #invoke. This has the disadvantage that it becomes more difficult to use the same #invoke somewhere else.