Many people in Bangladesh have two given names: a "good name" (ভাল নামbhalo nam), which is used on all legal documents, and a "call name" or "nickname" (ডাক নামđak nam), which is used by family members and close friends.
The two names may or may not be at all related; for example, a man named Šumon Saha (সুমন সাহা) may be called by his đak nam (e.g. Bubai বুবাই) at home and by his bhalo nam (Šumon সুমন) elsewhere. Many people also have a shortened version of their bhalo nam (e.g. Dipu for Deepak, Faru for Farhana, etc.) in addition to their full bhalo nam and their dak nam.
Though middle names are very common in Bangladesh, not every individual has one; this applies to West Bengal as well. Recently, many people have begun to add their dak nam to the middle or end of their full official name, resulting in names like "Saifuddin Kanchon Choudhuri" (সাইফুদ্দীন কাঞ্চন চৌধুরী), where "Saifuddin" would be the man's bhalo nam, "Kanchon" would be his dak nam and "Choudhuri" would be his family name. "Saifuddin Kanchon Choudhuri" could also be written as "Saifuddin Choudhuri Kanchon" dak nam in the end, depending on the choice of the person, how he/she displays their name. In these situations, this man would be correctly addressed "Mr. Choudhuri", not "Mr. Kanchon".
A majority of the people of Bangladesh are adherents of Islam, and because of this, they mostly use names of Arabic origins followed by Farsi, Bengali and Pali origins. Among Muslims of Bangladesh, there are several different naming conventions. There is no fixed scheme for the structure of names. Many people do not really use a family name, so members of a family can have different last names. The system of usage of different family names in the same family may also be followed by non-Muslims due to the dominating name style of not having same family names in a family by Muslims in Bangladesh. Some family names may be common between all religions like: চৌধুরী (Choudhuri / Chowdhury), সরকার (Sorkar / Sarker / Sarkar) and বিশ্বাস (Bishwas).
List of common family names by a person's religion
Mohammod, Muhammod or Muhammad (মোহাম্মদ) is a common prefix used before the name of many Muslim males, and it is not considered as the name used to refer to the person. In many cases, the "Muhammad" prefix is shortened to মোঃ ("Md.", or "MD."). Other common prefixes are not systematic. The prefix often serves as the first name and the given name appears as the last name/surname.