I haven't test throughfully but it seems to me that evernote contains:person does only recognized english "person names", I tried creating a note with an english name, a note with spanish name , a note with a chinese name , and a note with an indian name (all of them Firstname Surname form) .
Only the english note was recognized. I work with chinese and indian teammates and their names are often in my notes but I can't find any of those notes when I use "contains:person".
So, assuming that I'm right and that the "contains:person" is only for english names, would it be possible to expand it to cover that part of the population?