I just started reading a piano book (Pinao Lessons by Mantius Cazaubon). In chapter 1 explaining about keys and notes in the sections of The Black Keys and The White Keys. It is very clear from first two sections that white keys have one name and black keys have two names viz., Sharp and Flat.
Now immediately followed after above sections there is Enharmonic Equivalents which is written as follows.
"When one key has more than two note names, the notes are enharmonic equivalents of each other. C sharp and D flat are enharmonic equivalents. D sharp and E flat are enharmonic equivalents. F sharp and G flat are enharmonic equivalents. and so on."
I am thinking this is useful information explaining about the technical names and terminologies but my question is why author did not simply stating that "all black keys are enharmonic equivalents"? Have I missed anything?