Siman 454
Presented here for study, not as a practical ruling. The Shulchan Aruch rules by Sephardi custom, the Rema's glosses by Ashkenazi custom, and the Kitzur follows Ashkenazi custom. For a practical question, ask your rabbi.
א אֵין יוֹצְאִין לֹא בְּפַת סֻבִּין וְלֹא בְּפַת מוּרְסָן, אֲבָל לָשׁ הוּא אֶת הָעִסָה בַּסֻבִּין וּבַמּוּרְסָן שֶׁבָּהּ וְיוֹצֵא בָּהּ. וְיוֹצֵא בְּמַצָּה מִסֹלֶת נְקִיָּה בְּיוֹתֵר, וְאֵין אוֹמְרִים אֵין זֶה לֶחֶם עֹנִי. הַגָּה: וְטוֹב לְכַתְּחִלָּה שֶׁלֹּא לַעֲשׂוֹת הַמַּצָּה רְחָבָה יוֹתֵר מִדַּאי, דְּהָוֵי כַּאֲשִׁישָׁה (מַהֲרִי"ו).
1 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).
ב עִסַת הַכְּלָבִים, בִּזְמַן שֶׁהָרוֹעִים אוֹכְלִים מִמֶּנָּה יוֹצְאִים בָּהּ; וְאִם לָאו, אֵין יוֹצְאִין בָּהּ שֶׁאֵין זוֹ מְשֻׁמֶּרֶת לְשֵׁם מַצָּה. הַגָּה: כָּךְ הֵם דִּבְרֵי הָרַמְבָּ"ם אֲבָל יֵשׁ אוֹמְרִים הַטַּעַם מִשּׁוּם שֶׁאֵינוֹ קָרוּי לֶחֶם כָּל זְמַן שֶׁאֵין הָרוֹעִים אוֹכְלִים מִמֶּנּוּ, וְכֵן נִרְאֶה עִקָּר (טוּר י"ד סִימָן ש"ל וְר"ש בְּפֵרוּשׁ דְּמַסֶכֶת חַלָּה פ"ק).
2 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)
ג לֵיכָּא בַּזְּמַן הַזֶּה דְּיָדַע לְמִחְלַט, הִילְכָּךְ כָּל מִין חֲלִיטָה אָסוּר.
3 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.
ד אֵין אָדָם יוֹצֵא יְדֵי חוֹבָתוֹ בְּמַצָּה גְּזוּלָה. בַּמֶּה דְּבָרִים אֲמוּרִים, כְּשֶׁגָּזַל מַצָּה; אֲבָל אִם גָּזַל חִטִּים אוֹ קֶמַח וַעֲשָׂאָן מַצָּה, יוֹצֵא בָּהּ, שֶׁקְּנָאָהּ בְּשִׁנּוּי, וְדָמִים לְבַד הוּא חַיָּב לוֹ. וּלְעִנְיַן בְּרָכָה ע"ל רֵישׁ סִימָן תרמ"ט.
4 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)