What qualifies a 404 page for adsense?

[thok]

As most of us know that google recently updated there TOS saying that ads are allowed on all content pages, (even if they are on error pages like customized 404 page)

I want your opinion on it. What is content on the 404 page?
What qualifies a 404 page for adsense ?

[edited by: engine at 10:50 am (utc) on Jan. 30, 2009]
[edit reason] no urls, thanks [/edit]

[martinibuster]

From AdSense Program Policies [google.com]:

No Google ad may be placed on any non-content-based pages.

However the newly expanded AdSense for Domains [google.com] program allows you to place ads on pages with no content.

Instead of an "under construction" page or 404 error, AdSense for domains provides links, search results, advertisements and other content.