In college recruiting, I typically assume that if a student does not include their GPA on their resume, it does not meet our requirements which would be a red flag.
If your GPA is not listed on your resume we will assume that you probably don’t want to share what it is.
Grammar, spelling and formatting issues are large red flags. This is easily interpreted as carelessness, not taking the job search process seriously or issues when it comes to attention to detail.
[N]ot listing dates of employment - recruiters are typically looking for a steady history of employment and if the dates aren't listed they might assume the worst.
Another red flag is gaps in experience or school that are not explained. It is better to comment on gaps, even recognizing time off, than to leave the time unexplained.
[S]tay away from including too much personal information that may be considered "protected" information based on various employment laws (i.e. age, gender, disability, religion, race, national origin, ethnicity, etc).
Including personal data and/or photos on a resume opens the door to possible discrimination claims against employers, putting them in an uncomfortable spot. For this reason, they will often discard your resume without even looking at it.