Wikimedia Bugzilla is closed!

AFAIK, in the current {{...}} template mechanism, any argument whose key (parameter name) is not explicitly tested by the template's definition is silently ignored.  This behavior makes it nearly impossible for readers of a page to notice errors in template usage.  For example, the following call to Wikipedia's "cite book" template 

:: {{cite book | authro = P. Brown | title = Square Pegs | cover = hard | note = missing | year = 1950}}

yields only

:: <i>Square Pegs</i> (1950).

because all the other arguments are not explicitly used by the template code.

Suggestion: there should be a mechanism to make all unreferenced arguments visible.  One suggestion is to always typeset such arguments, with some glaring markup, at the end of whathever output the template code has produced.  For instance, the template call above coudl produce 

:: <i>Square Pegs</i> (1950) <font color="red"><b>| authro = P. Brown | cover = hard | note = missing </b></font>

Alternatively, there should be a special parameter name, say "LEFTOVERS", whose value at any moment is the concatenation of all parameter-value pairs that have not yet been explicitly referenced by the template code.  Thus, an "idiot-proof" template could finish its processing by fetching the "LEFTOVERS" string and typesetting it (properly un-wikified) with a glaring markup and/or warning message.