Must offensive words or names of actresses written on the Mushaf be erased, and is leaving them considered disbelief (kufr)?

Muslims have agreed on the obligation to venerate the Mushaf (definition) (Qur’an) and not expose it to desecration, for this is among the piety of hearts. Writing forbidden words, such as insults or names of transgressors, on the Mushaf contradicts its veneration. Therefore, these writings must be erased. Failure to do so, when one is able, is a sin, but it is not considered disbelief (kufr), for not everything that contradicts the veneration of the Mushaf constitutes disbelief.