If I will search title with one word, the Fess will make match phrase query the tile field: tile:word.
If I will try to use multiple worlds enclosed with quotes, then Fess will search also from other fields: title:“two words”
If I will give lang parameter in the url, it is ignored in the field query: /json?lang=sv&q=title:word
It also means if the title contains character with accents, the Fess will not find those cases: /json?lang=sv&q=title:åre
Fess version 13.10