How would CGC grade ? does ink pen written on back hurt overall grade ? 1 1

[jimjackjett]

So still kind of new to collecting and grading. Lets say I have this book and it has a number written on the back in ink pen. Does this affect the over grade that CGC would assign ?  So lets assume if there was no number written on the back and it would of received a grade of 8.0. Would the book still receive the 8.0 with this on the back or would it be penalized due to this ? Thanks

[The Lions Den]

My best guess is they would drop the grade a bit. In this case, an 8.0 becomes a 7.5. But who knows for sure?