A message being "gray boxed" means that it is minimized, and other users will have to click a gray box with the person's username to see the message in full.

These messages are not removed, they're only made less visible.
Many people (who prefer a less moderated experience) will still click the gray box so they can read these messages.

Typically, messages are gray boxed to de-emphasize certain content:

• Severe name-calling. See examples
  "You're a moron."
  "You're a troll and wasted of space."
  "You’re just a bitter old hag."
  
• Sex-related insults (sexual in nature, related to sexuality, or gender related). See examples
  "Sandra Keough is b***h"
  "Go back to OnlyFans, nobody wants your opinion here."
  "You probably haven’t gotten laid in years, that’s why you’re so bitter."
  
• Abusive, mocking, insulting, condescending, or any other broad or severe character attacks or sweeping negative generalizations, against:
  • Fellow forum members. See examples
    "Roger612 is a scumbag." (where "Roger612" is a forum member)
    "JaneDo3 is too stupid to know what she is talking about." (where "JaneDo3" is a forum member)
    
  • Groups of people due to their race, ethnicity, gender/sexual identity, appearance, disability, weight, or religion ("protected groups"). See examples
    "Trans people are disgusting and will destroy this country."
    "She is a fat pig."
    "XYZ religious people are a danger to society!"
    
• Complaints about the forum, forum rules, moderating or gray boxes might get gray boxed, especially if they're off-topic from the main discussion. See examples
  "The moderators here are crazy."
  "I hate this forum's moderation!"
  

Fastlane Posts In Non-Fastlane:

New discussions about politics, politicians, laws, and certain hot bed social issues should always be put in the "Fastlane" category or they might be gray-boxed. Why?

Am I In Trouble?

Getting a gray box is fairly common (1-2% of all posts), and doesn’t by itself mean you’re "in trouble." If the moderator really thinks you’ve crossed a line, you may get a Private Message about it.

However, a gray boxed message does mean that your post might be outside of the environment wanted on the forums, so please try to avoid repeatedly making posts if you know they will get gray boxed.

Gray Box Disputes

Under any message that has been gray boxed is a link to dispute the gray box. This will send a request to be reviewed again by a moderator to potentially remove the gray box from the message.

Trusted Disputers: If you regularly help out by disputing gray boxes correctly, you may also receive more privileges, such as being able to instantly remove gray boxes from messages after you dispute them (not having to wait for moderator review).

Enforcement:

If you get too many gray boxes in a short amount of time, your account may be put in temporary time out. If too high a percentage of your posts end up gray boxed, you may also get put in temporary time out. After one or two gray boxes in a day, you should probably slow down and think about what you're posting more carefully.