The community of Roblox is made up of players and developers of Roblox of all ages. Everyone works hard to create the environment that is safe and fun for all of the users. In order to aid this process, Roblox provides the users and the parents with numerous parental controls and safety features.
All the chat on the platform called Roblox is filtered in order to prevent the inappropriate content and personally identifiable information from being visible on the platform. There are two kinds of chats. The first one is the normal chat and the second one is the safe chat. However, the safe chat is disabled and now there are custom chat and normal chat.
In 2006, Roblox reduced the Core Scripts relating to the Chat Window to the level 2. This one allows the creators of the game to make the custom chat windows and make modifications. Even though it does open the chance for the inappropriate messages to be sent, Roblox demands that the creators use the thing called Chat:FilterString for system messages and anything extra, or else the game will be under review. On the other hand, it allows the creators of the game to make the chat window better match their game.
The second one is the normal chat. Since the year of 2014, the safe chat menu is disable, getting rid of the ability to chat from guests. However, all the players whose age is under 13 years old have the ability to chat only with words marked on the Whitelist. All the words not marked on that list are replaced with # or hashtags. Every player of Roblox whose age is 13 years or over is able to use any word, except the ones in the Blacklist. Basically, every explicit word marked in the Blacklist was replaced by “(Content Deleted)”. In order to prevent thus from happening, all the Roblox players censor their words by placing several spaces in their vulgar word or even make it look like one. Apparently, this was changed again to a # or hashtags.
This paragraph consists of the information about the safe chat. Safe chat was the name of the chat mode that prevented all the Roblox players that usually under 13 years old from typing the custom messages and numbers into the chat bar for the safety reasons, such as to prevent said users from typing expletives and or profanity. All those users were, however, allowed to chat the pre-programmed messages, yet could not type their won messages. For your information, the guests always had super safe chat on, unless it was changed by the exploit. Even though you are not able to access sueprsafe chat through the safe chat, it can still be used by the users that have the custom chat. The thing is that you are no longer use the command as the command or /sc was removed Mid-October 2016. For details, you can check the source such as Wiki and the Roblox community.