Map Comments are objects in the Waze map that appear as orange points and polygons in the Waze Map Editor. They only appear in WME and not in the Waze client app. They are used as notes, explanations, warnings or reminders for editors and can be made by any editor anywhere. They have no effect on routing and cannot be reported or searched in the Waze app.
Creating a Map Comment
Hover your cursor over the 
icon in the header bar and select the area or point option. Keep in mind that, while map comments are visible at all zoom levels, small area map comments may not be easily noticed at the lowest zoom levels. The title field is limited to 30 characters, so summarize the map comment's reason for existence in the title. The comment field is limited to 2000 characters, so a full explanation can be given there. Further comments can be made by other editors subsequent to the creation of the Map Comment, and notification for subsequent comments will be sent to the creator and to anyone who adds to the discussion, similar to how Update Requests work. To set an expiration, fill out both the date and time fields. The Map Comment will delete itself after the expiration time. It can also be locked as necessary, which will prevent editors of insufficient rank from commenting in, moving or deleting the Map Comment.
When to use Map Comments
Map comments should be used for anything that requires a note for oneself or other editors. In that past, editors used things like road segments or Update requests to make notes on the map, but these should be replaced with Map Comments. Possible uses may include unusual road configurations, detour prevention, places where the current map differs significantly from aerial or street view imagery, turn instruction overrides, temporary traffic changes or links to forum discussions.