The reasons why the word "Xu" cannot be used in names are as follows:
The word "Xu" means "sun", and the zodiac sign is tiger. This is a taboo word for tiger people to use in names, because tigers live in caves or under the shade of trees. They don't like being in the sun, so any words related to the sun and light are not suitable to be used to name babies born in the year of Tiger.
The word "Xu" counts 6 strokes in the standard mathematical strokes of the Kangxi Dictionary. It is a lucky number in nomenclature. Although you will encounter some hardships, it can turn bad luck into good luck, but you must pay attention to the matching to avoid problems. However, the three talents and five figures of mathematical good and bad luck need to be specifically combined with the surname and refer to the relationship between the five elements of heaven and earth personality.