for the collation of golden age as well as las vegas and los angeles both being us cities with english names i agree with you indeed a general category for riverine islands would be much better than category islands by river sorting the article in islands by river under g is logical but has the disadvantage of using an element that isn't displayed in the category listing as la cartuja is also in other categories i e category isthmuses we should still find a default sortkey that is consistent similar to the hague under h or la chaux de fonds under c as on and anywhere else i could find it i'd go for c user docu