Yesno:

-- Function allowing for consistent treatment of boolean-like wikitext input. -- It works similarly to the template.

return function (val, default) -- If your wiki uses non-ascii characters for any of "yes", "no", etc., you -- should replace "val:lower" with "mw.ustring.lower(val)" in the -- following line. val = type(val) == 'string' and val:lower or val if val == nil then return nil elseif val == true or val == 'yes' or val == 'y'		or val == 'true' or tonumber(val) == 1 then return true elseif val == false or val == 'no' or val == 'n'		or val == 'false' or tonumber(val) == 0 then return false else return default end end