Is it permissible to write the name of the deceased on copies of the Holy Quran endowed as a perpetual charity for them, or is it sufficient to supplicate for them without mentioning their name?

The basic principle concerning things is permissibility unless there is evidence of prohibition. Therefore, there is no objection to writing the name of the deceased on a waqf (endowment) Qur'an as an ongoing charity for them, unless the intention is boastfulness. It is preferable not to write it, however, because secret charity is better than open charity, as Allah Almighty says: "If you disclose your charities, it is well; but if you conceal them and give them to the poor, it is better for you, and He will remove from you some of your evil deeds. And Allah is acquainted with what you do." As for writing a supplication for the deceased without their name, there is no harm in it. The words of Allah Almighty must be glorified, and the phrase "Qur'an booklets" is not suitable for that, as Allah Almighty says: "That [is so]. And whoever honors the symbols of Allah - indeed, it is from the piety of hearts."