Is it permissible to write the supplication for entering the lavatory on a paper on the bathroom door?

It is permissible to hang adhkar (remembrances of God) for the purpose of reminding, provided that they are hung in a suitable place, to preserve them. For example, the dhikr for entering the lavatory can be placed next to the bathroom door from the outside. Sheikh Ibn Baz was asked about placing verses or adhkar on walls for remembrance, and he answered that it is permissible if it is for benefit. Sheikh Ibn Uthaymeen agreed to writing down ahadith (prophetic narrations) that contain benefit for the purpose of remembrance.