In a definition of Неопределенные местоимения I see: Для обозначения неопределенного лица, предмета или признака служат Неопределенные местоимения. In my grammar I studied that "Indefined pronouns are those designing in a general, indeterminate way the persons or things to whom they refer".
Putting apart that in a definition the "indetermination" belongs to the way and in the other to the object, my question refers to the word "признак" that I see translated in my dictionary as: sign, indication, sympton. Less use has, I think, the phrase: служить признаком (to serve as a sympton).
In other Russian grammar I see again about these pronouns: "употребляются тогда, когда говорится о лице или предметe неизвестном...". What does mean this word признак in the first definition? Thanks