Google has deleted and 404ed the Rich media file best practices. Google said removed its "documentation about rich-media files, such as Silverlight and Flash." Why? This is the best part, Google wrote "turns out it's not 2005 anymore."
You can probably briefly see the cached version of the page over here and then use the Wayback machine to look it up when that goes away. But here is a copy and paste of the page:
Rich media file best practices
Google can index most types of pages and files. Here are a few details about some specific rich media types:General best practices
If you do plan to use rich media on your site, here are some recommendations that can help prevent problems.- Try to use rich media only where it is needed. We recommend that you use HTML for content and navigation.
- Provide text versions of pages. If you use a non-HTML splash screen on the home page, make sure to include a regular HTML link on that front page to a text-based page where a user (or Googlebot) can navigate throughout your site without the need for rich media.
This doesn't mean that you can't include rich media content such as Silverlight or videos on your site; it just means that any content you embed in these files should also be available in text format or it might not be accessible to all search engines. The following examples focus on the most common types of non-text content, but the guidelines are similar for any other types: provide text equivalents for all non-text files. (Also note that Flash is no longer supported.)
This will not only increase Google's ability to successfully crawl and index your content; it will also make your content more accessible. Many people, for example users with visual impairments, who use screen readers, or have low bandwidth connections, cannot see images on web pages, and providing text equivalents widens your audience.
Video
See video best practices.IFrames
IFrames are sometimes used to display content on web pages. Content displayed via iFrames may not be indexed and available to appear in Google's search results. We recommend that you avoid the use of iFrames to display content. If you do include iFrames, make sure to provide additional text-based links to the content they display, so that Google can crawl and index this content.Flash
Flash is no longer supported. We recommend using a different format, such as HTML5.----
So this is no longer relevant - do you miss Flash or Silverlight? :)
Forum discussion at Twitter.
