About filtered HTML
When you publish a Web site to the Web using the Publish to the Web command (File menu), Publisher converts your Publisher file (.pub) into smaller filtered HTML files that can be published to the Web more quickly. Publisher encodes its filtered HTML with Vector Markup Language (VML) information that speeds up the downloading time for graphics on your Web site.
You cannot edit a Web page in Publisher when it is saved as filtered HTML. To edit a Web page in Publisher, save a copy of your Web site to your local computer as a .pub file. To make changes to your published Web site, edit the original .pub file in Publisher, and then publish it again.