This entry is more geared towards job seekers rather than recruiters.
It is something simple that can lead to a bit of confusion and prevent you from getting submitted or it may lead to you falling through the cracks and that is nicknames.

Lets say your name is Ray Jay Johnson Junior.

I would drop the Junior and go by the same name through out the process.

If your resume lists your name as Ray, be Ray through the entire process. Never say, "You can call me Jay" because someone may ask for Jay's resume and the person searches their database and cannot find it.

This goes for Meg/Megan or Bill/Will/William or Jen/Jenny etc.