Good idea, Giovanni... a site admin can add multiple stamps in the Annotate PDF plugin for Moodle's Assignment. You could turn your proofreading marks into image files that you can add as a stamp to a submitted text.
Also, this plugin may be of use: https://moodle.org/plugins/atto_corrections
Also, this plugin may be of use: https://moodle.org/plugins/atto_corrections