h-review

 h-review  is the microformats2 vocabulary for marking up review posts on web sites.

Why
h-review is the simplest way to markup a review so that it has a chance of being consumed by readers, aggregators, etc.

How to consume h-review
Use a microformats2 parser as you do for posts in general.

You may treat an h-review similar to a comment, however, you should at least be ready to handle an empty comment/summary/content field, and look for (and handle) at least the optional fields of:
 * rating
 * tags

Publishers
See and add to review: IndieWeb Examples instead of here.

Consumers

 * Breakfast and Coffee accepts h-review documents via webmention. Upon sending a h-review to Breakfast and Coffee, the wiki will add your review to the aggregate review page that relates to the place you are reviewing. If no aggregate review exists, a new page will be created and the provided h-review will be at the top of the Review section in the new aggregate page.