Regarding the possible significance of the single letters called al-muqatta'at, which occur at the beginning of some surahs of the Qur'an, see Appendix II, where the various theories bearing on this subject are discussed.
Malik Quran Translation
Alif Lam M'im.
Yusuf Ali Quran Translation
Yusuf Ali Translation Note Number :
These are abbreviated letters, the Muqattaat, on which a general discussion will be found in Appendix I (to be printed at the end of this Sura).
Mustafa Khattab Quran Translation
Mustafa Khattab Translation Note Number :
See Stylistic Features for information about these letters.