Is it permissible to write the Basmalah (saying, "Bismillah Al-Rahman, Al-Rahim [In the Name of Allah, the Most Gracious, the Most Merciful]") at the preface of any writing?
It is Sunnah (action following the teachings of the Prophet) to write it at the beginning of any important writing, (Part No. 4; Page No. 187) because the Prophet (peace be upon him) used to begin his letters with it. It is also reported that the Prophet (peace be upon him) said:
Every important matter that is not prefaced with ‘Bismillah’ (In the Name of Allah) is maimed (i.e. Severed from blessing).
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.