אין יוצאין לא בפת סובין ולא בפת מורסן אבל לש הוא את העיסה בסובין ובמורסן שבה ויוצא בה ויוצא במצה מסלת נקייה ביותר ואין אומרים אין זה לחם עוני: הגה וטוב לכתחלה שלא לעשות המצה רחבה יותר מדאי דהוי כאשישה: (מהרי"ו)

Those Matzot with which one does not fullfil his obligation. Containg 4 section One does not fulfill his obligation with husk bread, bran bread, rather, one may knead husks and bran into a dough and fulfill [the obligation] with it. One may fulfill [the obligation] with fine flour Matzah which is excessively clean and we don't say that this is not Bread of Affliction Rema: and it's initially better to refrain from making the Matzah excessively wide to the extent that it is like a big [Ashisha] loaf (Ma"hariv).

Regarding] dogfood dough, when the shepherds are eating from it, one may fulfill his obligation with it and if [they are] not, then one may not fulfill his obligation with it as this was not guarded for the sake of Matzah. Rema: These are the words of the Rambam, however, there are those who say the reason is that [dough] cannot be described as bread whenever shepherds refrain from eating it and this appears to be the accepted principle (Tur Y"D 330 and Rash in explanation of Tractate Challah Ch. 1)

Contemporarily, there is nobody who knows how to 'fully cook flour without any leavening' [chalatt]. Therefore, all forms of 'fully cooking flour without any leavening' are forbidden.

A person cannot fulfill his obligation with stolen Matzah. Regarding what were these matters said? When one stole Matzah, but if wheat or flour was stolen and made into Matzah, one fulfills his obligation with it because he annexed it through transformation and now he is only obligated for the value (and regarding the principles of blessing, see earlier at the beginning of siman 649)