Sefer - Seforim - Tefillin - Mezuzah

differences and similarities

explanation of open and closed paragraphs (pesucha and stuma)

forgot to write God’s name then wants to insert it

halachah LeMoshe MiSinai and other halachah related to the writing and constructing of seforim, tefilin, and mezuzos

letters written over a hole in the parchment

limits to erasing then inserting, missing, or torn text

sefer when not in use should be turned over with the writing facing down

writing God’s name with a prefix