I suppose you mean as a tag of sorts, similar to the planned feature of NSFW tags? Otherwise, this could just be part of the description of the project.

Going to add please list examples of mild & course language. I've had to ask over and over if a project has xyz SPECIFIC words (like f, b, sh, etc), because people's opinions about mild, course etc varies.

When i used to ask if a project had crude, vulgar, or bad language, i received varying responses.

Please provide a concrete guide to go with this. Thsnks.