I have a friend named Abdul Razzaq. People often call him Razzaq. I believe it is an indefinite name. I used to tell not to call but still friends call him saying that they are not meant the indefinite name. My question is that can we call like that and if not how to deal or correct it?

It is a good practice of Islam to name oneself or name his offspring Abd' (i.e, slave of, for boys) or Amah (i.e, female slave of) along with One of the Most Exalted Names of Allah: For example, a boy can be named Abdul-Waahid or a girl can be named Amatil-Waahid. However, we should avoid naming someone after names that are not authenticated strongly in the texts of Qur'an and Sunnah: For example, Abdul-Rasheed or Abdul-Sabuur or Abdul-Mun'im.

On the other hand, naming oneself after one of the names of Allah word for word like Raheem or Hakeem is permissible with exceptions: For example, one should never name himself Allah, or Rahman, or Ahad (i.e, The One), or Samad (i.e, One whom all creatures need and He does not need anyone), or Khallaaq (i.e, Creator Supreme), or Jabbaar (i.e, One who cannot be resisted), or Mutakabbir (i.e, Full of Pride), or Atheem (i.e, The Greatest), or Hayy (i.e, the Everliving), or Qayyum (i.e, Self-subsisting), or A'laa (i.e, Most High), or Akram (i.e, Most Noble), or Razzaaq (Sustainer Supreme), or Mannaan (i.e, The Benefactor), or Dayyaan (i.e, the Final Supreme Judge), for those names are exclusively for Allah Most High.

Similarly, other names should be approached carefully so that one should not name himself Maalikul Mulk (i.e, Owner of All), or Rabbul 'Aalimeen (i.e, Lord of the Worlds), or Rabbul A'laa (i.e, Lord Most High), or Aalimul Ghayb (i.e, the knower of the unseen), for such exaltation belongs only to Allah, but one can be called Maalik for instance. It is not recommended, though, to name oneself word for word Allah's Names unless it is accompanied by Abd' or 'Ubayd or Amah, to demonstrate clearly our belonging to Allah as we are His own hand-crafted slaves and creation.

On the opposite, it is not permissible to use the prefix Abd' or Ubayd or Amah expressing servitude to other than Allah: For example, Abdul-Rasool (i.e, the slave of the Messenger), or Abdul-Shams (i.e, the slave of the Sun), or Abdul-Hassan (i.e, the slave of someone named Hassan).

And Allah knows best.