id,summary,reporter,owner,description,type,status,component,version,severity,resolution,keywords,cc,stage,has_patch,needs_docs,needs_tests,needs_better_patch,easy,ui_ux 17179,yesno arg is optional,CarlFK,nobody," ""Given a string mapping values for true, false and (optionally) None, returns one of those strings according to the value:"" https://docs.djangoproject.com/en/dev/ref/templates/builtins/#yesno Looking at the code, I see the string is optional. if arg is None: arg = ugettext('yes,no,maybe') http://code.djangoproject.com/svn/django/trunk/django/template/defaultfilters.py ",Cleanup/optimization,closed,Documentation,1.3,Normal,fixed,,,Accepted,0,0,0,0,1,0