For my upper-level students (French IV and AP), I use this when we write compositions in class.
Students submit their rough draft and I mark it up with these symbols. Students then correct the errors on their own. Symbols include things such as:
-problem with agreement (masc./fem, adjective, past participle)
-verb should be reflexive
…and so on
I've found that using this has really let my students see where they make the most mistakes, and encourages them to take responsibility for their writing.
This is also good for peer editing -- students can work together to help correct each others' paper.