1) If someone has in mind a certain name to be given to his son, but while the
blessing (“preserve this lad …”) is being said, when the one reciting the
blessing reaches the passage “and may his name be called in Israel …” the
father specifies a different name from the one he had in mind, the son should
remain with this different name.
2) If the one reciting the blessing gives a name that is different from the one
that the father instructed him to say, we need not worry about it; the son
should remain with only the name specified by the father.
3) If one names his son after a deceased relative, and it is later discovered that
the relative is in fact still living, we need not worry about this departure
from the usual custom of not naming after living people, since when the name was
originally given, they were unaware that he was alive. Some say, that they
should add an additional name, but not remove the original name. Others add that
if the family objects, then they may even remove the original name.
4) If a child has been given two names, and afterwards they remember that the
child’s grandfather bears one of these two names, then the child should not be
called by this name, but only by his second name. This also applies to the
English name - he should not be called by that name.
5) If an additional name has been given to a sick woman, and it is later discovered
that this added name is the name of her sister, then even if thirty days have
elapsed, they should add yet another name, and this name should be kept.