1) Nowhere in the Talmud do we find a Tanna or Amora who is called by two names. Even in the Biblical texts we do not find one person called by two names. Nevertheless, these days it is common to give more than one name to the same child. Others object to giving one child two names, even in our days.

2) A single name may be composed of two names; for example, Schnei Or and Shem Tov.

3) Occasionally, a child is given a proper name after one person, and a nickname (secondary name) after another person, even when the nickname bears no relation to the proper name.

4) If a person becomes seriously ill, he is given an additional name.

5) If one’s earlier sons died as a result of circumcision, and then another son is born to him, some are accustomed to give this son two names.

6) Some say that the names of two different people should not be combined and given to a single child. Others are not particular about it.

7) One child should not be given the combined names of two people who feuded with each other during their lifetime, even if both of them were tzaddikim.

8) Some say that one should not give his son the combined names of his father and his brother (the child’s uncle), but that he should give the child his father’s name only.

9) Some say that one should not give his son the combined names of his father and his father-in-law, but only the name of his father. Others dispute this.

10) One should not combine the name of a family member with the name of a Rebbe.

11) If a child is given two names after two different people, it is proper to call him by both names.

12) If one’s parents are still living, and have two names, there is no objection to giving his son or daughter one of the two names. The same applies to the opposite case - i.e., he wishes to give his child two names, and the parent has only one of the names.