Complex sentence: DSC comments that serve this second function are more akin to preprocessing directives and are not purely comments; documents using those kinds of DSC comments require a functioning document manager to come out as intended, sending them directly to a printer will not work.
Split into simpler sentences: DSC comments that serve this second function are more akin to preprocessing directives and are not purely comments. Documents using those kinds of DSC comments require a functioning document manager to come out as intended; sending them directly to a printer will not work.