1,721. Filling in the Blanks
Hilchos Geirushin 3:7
In order to make things easier for scribes, the Sages permitted them to write the boilerplate portions of a get in advance, leaving blank spaces for the couple’s names, the date and the sentence saying that the woman is now permitted to marry any man. The scribe then writes these portions specifically for this man and this woman, after which the witnesses sign it for this specific couple.
Hilchos Geirushin 3:8
Let’s say that a scribe wrote a get properly for a specific couple but the witnesses signed it without that intention. Since the man delivers the get in front of witnesses, the get is effective Biblically but not rabbinically. The reason it’s not thoroughly invalid is because the necessity for witnesses to sign a get was only instituted as a societal benefit. There is an opinion that a get is completely invalid if the witnesses signed without proper intentions, like a forged get. They likewise opine that if one witness was unacceptable, or if the get was signed by only one valid witness, it is invalid even if it was delivered in front of valid witnesses. The Rambam disagrees with such opinions saying that even though the get resembles a forged get, it’s not really a forgery. Therefore, since it was delivered in front of valid witnesses, the get is only unacceptable at the rabbinic level.