Dear w3c team member, I was using code
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Frameset//EN" "http://www.w3.org/TR/REC-html40/frameset.dtd";> copied and pasted from Your page http://www.w3.org/TR/1998/REC-html40-19980424/present/frames.html to declare a frameset and got the following error message from Your validator http://validator.w3.org/: Mismatch between Public and System identifiers in the DOCTYPE declaration This document uses an inconsistent DOCTYPE declaration. The Public Identifier -//W3C//DTD HTML 4.0 Frameset//EN declares the HTML 4.0 Frameset document type, but the associated System Identifier http://www.w3.org/TR/REC-html40/frameset.dtd does not match this document type. With respect Dominik Lenné, Berlin
