The statement in the introduction says:

"When the polarity of the battery is such that electrons are allowed to flow through the diode, the diode is said to be forward-biased. Conversely, when the battery is “backward” and the diode blocks current, the diode is said to be reverse-biased."

It is best to rephrase it as follows:

"When the polarity of the battery is such that a current is allowed to flow through the diode, the diode is said to be forward-biased. Conversely, when the battery is “backward” and the diode blocks current, the diode is said to be reverse-biased."

This revision eliminates confusion in the current flow convention (flow of current to be from positive to negative poles in a DC circuit vs actual case of electrons moving from negative to positive poles), and follows with the remaining part of the sentence when it refers to current.

 

There is no confusion as to current flow conventions, as this was stated in the beginning of the book, as well as a sticky in the front of this forum. The book is internally consistent throughout. IMO, this change is not needed. In spite of the long discussions to the contrary, electrons are the charge carriers of electricity in a wire.

However, this is not my call, Dennis will review and decide if the change is warranted.