I. All posts should be related to the box office or the business of movies. Significant pre-release updates about an individual movie are also acceptable if they could have a major impact on the film’s box office performance (so a first trailer or Rotten Tomatoes consensus post is acceptable, but no random character posters and that kind of stuff).
II. Every post needs a region tag in its title. These help people know which region your box office info is coming from. Examples include [NA], [UK], [Worldwide], etc. A full list of tags can be found over here. If a post doesn’t have a particular region associated with it, use [Other].
III. Don’t be an asshole. No trolling, flaming, or illegal content. Be respectful of other people’s opinions even if you disagree with them, nobody knows for sure how well a movie will do until it opens.
IV. No duplicate content. Don’t submit the same article twice. A post with a box office update for only a single movie should be notable in some way (e.g. passing a major milestone, a significant international opening).
V. No low-quality content. Posts from Forbes and other websites that often have clickbaity titles will be automatically removed, you can contact the moderators to have your post manually approved. Don’t submit articles that just rephrase another site, submit the original source website instead. Memes and other joke posts are better suited for /r/boxofficecirclejerk.
List of common box office terms
List of movie abbreviations
An analysis of Cinemascore
Box Office Mojo - the definitive source for box office statistics, also home to good weekend box office updates.
Box Office Pro - best known for their long-range forecasts of domestic openings.
The Numbers - an alternative to Mojo with some improved comparison features.
Box Office Report - a source for box office updates, with great pages comparing a movie's opening weekend numbers to its trailer views and preview night results.
Box Office Theory - popular box office forum.
Deadline - has the most comprehensive box office analysis of all the trades.
The Hollywood Reporter
International Box Office
entgroup.cn - reports on the Chinese box office regularly.