Section 21.7.3 Placement of Pronunciation Keys says they are inserted before the alphabetic reference material. It goes on to state, "When an alphabetic reference is longer than a single volume: . . . e. The pronunciation key is inserted in the front matter of each volume when pronunciations appear throughout the text." The way I read this rule, subsection e applies only if the reference is longer than a single volume. There were pronunciations throughout the text, so does the key need to be in the front matter even if the alphabetic references are only a few pages long? If so, shouldn't subsection e be a separate rule that is not connected to 21.7.3?
Thanks for the interesting question. The Formats document was created by actual human beings and is therefore, not a perfect work. However, it is what we have. It is also a constant work in progress and possibly that situation might be addressed, along with many others, in the upcoming update. The question is about placement of the pronunciation key when pronunciation are present throughout the volume. In that case, the key still needs to be in the front matter of the volumes. That material still needs to be easily accessible to the reader.