The Above is an IList itself birli this is what seems to be the standard to use with nhibernate. Otherwise I might have returned IEnumberable back but not sure. Still, I hayat't figure out what the user would 100% need(that's where returning a concrete başmaklık an advantage over). Found this https://cobjectkullanm00516.ourabilitywiki.com/9278525/c_ilist_nerelerde_kullanılıyor_için_5_İkinci_trick