The additions of this version focus mainly on the oblique shock and related issues as results of questions and reactions on this topic. However, most readers reached to www.potto.org by searching for either terms ``Rayleigh flow'' (107) and ``Fanno flow'' ((93). If the total combined variation search of terms ``Fanno'' and ``Rayleigh'' (mostly through google) is accounted, it reaches to about 30% (2011). This indicates that these topics are highly is demanded and not many concerned with the shock phenomena as this author believed and expected. Thus, most additions of the next version will be concentrated on Fanno flow and Rayleigh flow. The only exception is the addition to Taylor-Maccoll flow (axisymmetricale conical flow) in Prandtl-Meyer function (currently in a note form).
Furthermore, the questions that appear on the net will guide this author on what is really need to be in a compressible flow book. At this time, several questions were about compressibility factor and two phase flow in Fanno flow and other kind of flow models. The other questions that appeared related two phase and connecting several chambers to each other. Also, an individual asked whether this author intended to write about the unsteady section, and hopefully it will be near future.