Minimum lv to join a party

[Batman]

I have nothing against players from same guild that join a party , but generally the players should be like 10-15 levels lower/higher than the party lider. For example : if the party lider is lv30 then for a lv15-20 player should be ok to join but if a new player (lv1) join the game and find a lv35-40 afk then is not ok