Space for over 600 names and addresses in alphabetical order, 4 per pageEach page has the relevant letter conveniently written at the outer bottom edge.
The number of pages for each letter varies depending upon popularity - no point in having as many for xyz as you have for the most popular
12 unlettered pages at the end of the book, to use as an overflow if any set of letter pages fills up.
Each entry has space for Name, Address, Email,...