Abstract
The possibility of the coexistence of different kinds of BLR clouds in quasars (and Sy 1's) has been discussed recently in the literature. These clouds, photoionized by the UV central continuum would have different opacities and ionization states (HIl or HI* dominated clouds). In this work we analyze observational evidence (in particular, MgII and SiII lines in quasars) in favor of the coexistence of these clouds as well as mechanically heated clouds (where lines are emitted following collisional ionization).
