Language options include several language choice lists (UI and locale language, default languages for documents), as well as default currency list, all of which include a special item "Default: <Name>", which means that this setting becomes "unset" and defaults apply to it.
The item is sorted among other items alphabetically, making it appear somewhere among languages starting with the same letter as the word "Default" translated to current UI language. It is not obvious where to search for the item, because if there are no default items on the page, one has to guess which term (and which translation) was used: is it "Standard"? or "Default"?
The proposal is to make the items not sorted (topmost; maybe separated from the rest of list by a horizontal line, like last-used fonts in font drop-down in Formatting toolbar).
Agree, Default entry should appear at top of listing and be unsorted--that is the better UI. And a separator would be helpful.
A code pointer (for an implementation): see OfaViewTabPage::OfaViewTabPage in cui/source/options/optgdlg.cxx (Options ▸ LibreOffice ▸ View), which populates icon style list box, setting the "automatic" entry as the first element, and puts a separator after it.
... and the code populating the language lists is also in that file, in OfaLanguagesTabPage::OfaLanguagesTabPage, where the lists (e.g., m_pWesternLanguageLB) are set to sorted; and InsertDefaultLanguage is called.