Complex sentence: And a person is "not" allowed to edit or redact "other" people's comments, except in very limited administrative circumstances (such as striking the votes of banned or blocked users) that aren't applicable here.
Split into simpler sentences: And a person is "not" allowed to edit or redact "other" people's comments. What you're not allowed to do is edit or alter "other" people's comments, except in very limited administrative circumstances, such as striking the votes of banned or blocked users, that aren't applicable here.