KDE, because it runs on platforms other than Linux, has created its own locale information environment. The data stored is similar to other locales, including date and time formats, etc.
Most of the entries are self explanatory. All of the initial Name[xx] entries are supplied by translators for those languages and are most probably already complete.
Note that Languages defines what languages are used in this locale. Make sure that the first entry is the language that you want to be the default for your country.