The MacTech Print Ad Mechanical Requirements link on that page works, but it, like the Dates and Deadlines link is going to a URL with .html at the end, but the same links in the Advertising drop down button at the top are sans html.
Also somehow I got to this page when clicking one of the links or drop downs, I can't for the life of me find it now. It was the reason I posted this but after clicking around I found more and lost my trail. It was one of the Dates and Deadline links, can't remember for sure if it was the Advertising drop down or a link. I'm leaning towards one of the Advertising drop downs on some page. I'll try and find it again.