The Shulchan Aruch · Yoreh De'ah
יורה דעה רע״דYoreh De'ah 274
Siman 274 of 402 in Yoreh De'ah — 7 se'ifim
הלכות ספר תורהA Torah Scroll· siman 274
Se’if 1א׳
צָרִיךְ שֶׁיֹּאמַר הַסוֹפֵר כְּשֶׁיַּתְחִיל לִכְתֹּב: סֵפֶר זֶה אֲנִי כּוֹתֵב לְשֵׁם קְדֻשַּׁת סֵפֶר תּוֹרָה. וּמַסְפִּיק לְכָל הַסֵפֶר.
The scribe must say when he begins to write: I am writing this book for the sake of the holiness of a Torah scroll. And it suffices for the whole scroll.
Se’if 2ב׳
צָרִיךְ שֶׁיִּהְיֶה לְפָנָיו סֵפֶר אַחֵר, שֶׁיַּעְתִּיק מִמֶּנּוּ, שֶׁאָסוּר לִכְתֹּב אוֹת אַחַת שֶׁלֹּא מִן הַכְּתָב. וְצָרִיךְ שֶׁיִּקְרָא כָּל תֵּבָה בְּפִיו קֹדֶם שֶׁיִּכְתְּבֶנָּה.
He must have another scroll before him from which to copy, for it is forbidden to write one letter that is not from a written text. And he must read each word with his mouth before he writes it.
Se’if 3ג׳
יִכְתֹּב כְּתִיבָה נָאָה וּמְיֻשֶּׁרֶת, תַּמָּה. וְאִם כָּתַב אָלֶף לָמֶד בְּיַחַד, כָּזֶה ﭏ, אֵינוֹ כָּשֵׁר.
He shall write a handsome, even writing, complete. And if he wrote alef and lamed joined together as a single character, it is not fit.
Shulchan Aruch, Yoreh De'ah — Torat Emet 357 edition, via Sefaria — public domain
English rendered from the Hebrew for this app — The Gematria's own rendering program. A rendering of the words, not a ruling; practical halacha is learned with a rav