Lately, in processing reciprocal link requests made to our sites, I've seen a growing number of requests from sites that use a coding process that I've never seen before. When I check the source code to make sure that they're not blocking spiders from the page, I find that the code has no HTML tags, no HEAD tag and no BODY tag. All it has is the coding for what appears on the page.
In most cases, such pages have had a PR of 0, so I've written off those sites as using some sort of deceptive practice to conceal their outgoing links from the spiders. But lately I came across one that actually had a PR, which causes me to question my previous assumption.
Anyone know about this kind of coding practice? Is it a spider blocking trick or just a legitimate alternate coding practice?