The gemara [Gittin 20b] says that if one WRITES [כתב] a get on a golden plate and gives it to a woman as a get and payment for her ksubah at the same time it is valid.
The Rambam paskens this [even though some other halachos in the same sugya are strangely omitted... - maybe for another time] but alters the wording of the gemara and says that the get was ENGRAVED - חקק.
What did the Rambam find wrong with the gemara's terminology??