1)    1) One may not fast on the thirty third day of the Omer, nor may one eulogize, nor do we say Tachanun.

2)    2) There are those who say that the reason that there is a custom to light bonfires on this day is because of what the Zohar says that on the day of the decease of Rabbi Shimon Bar Yochai he revealed much of the secrets of the Torah, and a heavenly fire took hold in the house because of the extent of the holiness in the house, and in memory of that fire we light a bonfire on that day.