Changes
use standard contentlanguage; if you need to fallback to some specific language, use {{fallback|Template name|the-specific-language}}
{{#ifexist: Template:{{{1|}}}/{{#if: {{{2|}}} |{{{2}}}|{{int:Lang}}}} | {{#if: {{{2|}}} |{{{2}}}|{{int:Lang}}}} | de {{CONTENTLANGUAGE}}}}<noinclude>
{{documentation}}
[[Category:Localisation templates]]
</noinclude>