Only one profile keyword on a line.
The root_device keyword if the systems being upgraded by the profile have more than one root file system that can be upgraded (if you are creating a profile to perform upgrade installations).
A profile allows:
A comment after the pound sign (#) anywhere on a line. If a line begins with a #, the entire line is a comment line. If a # is specified in the middle of a line, everything after the # is considered a comment.
Blank lines.