Directly from the stickied Law thread. All new reviews will be held to these standards:
A minimum quality will be enforced on all reviews posted in the Map Review forum, regardless of the thread's origin (ie. a moved thread will still be held under these guidelines). In general, reviews should be of a decent enough quality so that the map's author (who will undoubtedly read the review given enough time to find it ) will be able to gain more insight about his/her work.
1. Reviews must include a written analysis of or discourse on the map. A standard paragraph size is an acceptable minimum.
2. The author of the map and the Battle.net title of the map (if any) must be present and clearly visible in the original post or the thread title.
3. A score does not need to be given, but a general opinion of the map must be present in some form.
4. Insulting the author of the map is prohibited unless the insult is harmless and used for comedic value.
4.a. No insult will ever be condoned if the map author is offended or in any way discouraged from map-making by it.
Breaking any of the laws in Section III. are considered minor infractions. In most cases, an offending review thread will be left open so that the reviewer may fix any issues with it. However, depending on severity, III.4.a may cause a major infraction. For the corresponding penalties, see Section I. and Section II.