"For" means that the MEP voted for extension of Chat Control 1.0

"Against" means that the MEP voted against the extension of Chat Control 1.0

I genuinely mean no disrespect here, but if the title reads as cryptic, your sources haven't been fully informing you about the issue. "Derogation from certain provisions of the ePrivacy Directive" is just what Chat Control (or at least Chat Control 1.0) means.