to $SrTiO_{3}$ (and $TiO_{2}$), are most probably responsible for high $T_{c}$. It turns out, that the most important results in $1ML$ $FeSe/SrTiO_{3}$ (and also $1ML$ $FeSe/TiO_{2}$), related to the existence of quasi-particle *replica bands* - which are identical to the main quasiparticle band [@Lee-Interfacial-supplement], [@Rebec-FeSe-TiO2], [@Replica-bands], can be coherently described by the $EPI-FSP$* *theory. This approach was proposed in seminal papers [@Lee-Interfacial-supplement]-[@Johnston1-2]. The beauty of these papers lies in the fact that they have recognized sharp replica bands in the $\acute{A}RPES$ spectra and related them to a sharp forward scattering peak in the $EPI$. (This is a very good example for a constructive cooperation of experimentalists and theoreticians.) Let us mention, that the $EPI-FSP$ theory was first studied in a connection with $HTSC$ cuprates [@Kulic-Zeyher1-2], while the extreme case of the $EPI-FSP$ pairing mechanism with delta-peak is elaborated in [@Dan-Dol-Kul-Oud] - see a review in [@Kulic-PhysRep]. Physically, this (in some sense exotic) interaction means that in some specific materials (for instance in cuprates and in $1ML$ $FeSe/SrTiO_{3}$) electron pairs exchange virtual phonons with small (transfer) momenta $q<q_{c}\ll k_{F}$ only, and as a result the effective pairing potential becomes long-ranged in real space [@Kulic-PhysRep]. It turns out that this kind of 