-addftr template: pers?clnt=<name|pass>&com=addftr&<ftr_1>=<def_val_1>&<ftr_2>=... Order of query params is not important. Feature names must not end with '*' to be legal. descript: inserts new (feature, default value) pairs. Must be used while initializing the personalization service For features that are added at a later stage, the profile of all users is updated to include them as well. If one or more feature names already exist in DB, or if one or more feature names are not legal names, code 401 (request error) will be returned. If the error code 401 is returned then none of the feature pairs in the request has been inserted in the DB. example : pers?clnt=name|pass&com=addftr&lang.en=0&lang.fr=0&lang.gr=1 returns : 200 OK, 401 (fail, request error), 501 (fail, server error) 200 OK : no response body exists.