From the Weekly News section at diamondcomics.com - the July 22nd edition, found in the Consumer News Archive, says the following (under Product Updates):

Product Updates
New information on products since Previews was released.

PRODUCT UPDATES for Items in the AUGUST PREVIEWS
MAGAZINES
• On page 348 of the August Previews, an ad for Comic Book Marketplace #96 erroneously notes that the book will contain covers and articles featuring the Spectre and Green Lantern. In fact, issue #96 is a resolicitation of an issue originally offered in the June Previews containing covers by, and articles about, Milton Caniff (AUG022418, $5.95) and Marc Hempel (AUG022419, $5.95). The issue will also contain eight extra color pages at no additional cost.