An untraceable URL is a "clean" URL. When searching for a book on Amazon, Amazon will add a "tail" to the searched book URL, adding information like the search terms used. It also includes which account made the search. If you share a link with anyone with all of this information attached, Amazon will know that it came from you, the author. The best practice is to remove all of the unnecessary information to avoid any problems with reviews being removed. The link should include the title (optional), DP, and the ASIN.- Once you have launched your book, if it is available via Amazon, ask your team to download the book directly from Amazon, even if they already received a free version from you before the launch. This will allow the purchase and the review to be verified. Verified purchase reviews are an important metric on Amazon and will show up before any unverified reviews. Note: Books downloaded through the Kindle Unlimited subscription may show up as unverified.