Kerbal Space Program Wiki:Templates
Data templates
Templates with most of it data which doesn't need to be translated can use a special system of storing the values in another template itself. This helps other languages to reuse these values directly and is used by all celestial objects with {{Planetbox}}. Because every article can be included via templates it is possible to add an article other articles. Templates which are in the Category:Translating Templates could be used for this method. It uses a subpage of the article in which the content/values are stored and the article with all the translation then imports this subpage.
For example he {{Planetbox}} template suggests to use /Data subpage which only holds the template contents which is then imported. So there is a Kerbol/Data article which only has the planet box values and Kerbol (also the different languages like Kerbol/sv or Kerbol/de) then imports this with {{:Duna/Data}}. The colon before the article's name is important, as without it, it would assume a template ({{Duna/Data}} would import Template:Duna/Data) and this would separate the specific values form the article.
If a template support this feature, it should use {{Data Template}} which automatically categorise the article and add a little help for all the users.