Items that are "rateable" signify to members that you are looking for honest, constructive feedback for that particular item. Members are able to rate your item and leave extensive reviews. This information is very important for authors looking to improve an item and, as such, reviews for each item are stored in the "Reviews" area of the item's header.
For even more information about your item and its readers, members with an Upgraded membership or higher receive demographic breakdowns through "Item Statistics" .

There are two rateable options to choose from:

Unrestricted
This is the default setting for new items. It allows members to leave a rating without a review or both rate the item and send a review. For the most feedback from readers and to get the most use from your Item Statistics, Writing.Com suggests using this option.

Rating Requires a Review
Items will not accept ratings unless accompanied by a textual review. Since the average rating for these items excludes non-reviewers, their rating average is only visible to the owner of the item.

Reviews Only; No Ratings
This option allows member to review your item without a numerical rating. Anonymous reviews are permitted and reviews will be stored and can be retrieved by the author.

Comments Only
This preference allows for feedback without utilizing the rating option. Members do have the ability to send the author an email regarding the item, but these emails are not permanently stored as a review. In addition, these emails will not be counted toward the reader's "Reviews to Ratings" ratio and are unable to be sent anonymously.

Why is there no option in the review box to make my comments public?
Members can only send the author comments on items that allow "comments only". Since they cannot be reviewed, there is no public review option.

Can I change an existing item to Comments Only? If so, what happens to the reviews and ratings?
Changing an existing item to Comments Only hides the ratings and reviews for that item and denotes to the community that the item is for showcase only. If you decide to once again reopen the item as rateable, those same ratings and reviews will reappear.

Why isn't my Comments Only item showing up on the public listings?
In order to give the most exposure to those in need of honest and sincere feedback, Writing.Com public listings by type and genre are reserved for rateable items only.

How can I promote my Comments Only item?
You can link it in your signature, forums, or anywhere you can post on Writing.Com, just like any other item. It is up to you to bring recognition to these items within the community. Some of the suggestions found in "Seeking Reviews"  may help you find ways to attract readers.

Can I see an example of a Comments Only item?
"An Example Unrateable Item" 

Can unrateable items receive Awardicons?
Yes.1