`invalid` Style Class

I noticed the invalid standard style class being noted for syntax highlighting. But there’s also the underline and line highlight for issues, and these can give descriptive feedback to the author. I was wondering then when the invalid scope name was intended to be used when authoring a syntax grammar.

invalid yields immediate feedback to the author and is quite eye-catching. I’m thinking maybe it could be used for situations such as having invalid escape sequences in strings, but I’m not sure I could justify that (or any situation) instead of just using an issue.