Frames

One of the features of HTML 4.0 deserves special attention with respect to search engines accessibility.  About half of the major search engines cannot penetrate framed sites.  For them, the root page of a frameset is all that can be viewed and indexed on the site, and all the framed pages below the root are missed.

The best solution for this problem (as well as for the problem of frames accessibility to people with disabilities; see Chapter 42, "Creating Widely Accessible Web Pages") is the NOFRAMES element.  It should be placed within the FRAMESET element, usually before the first FRAME tag, and may contain any text, links, or other material.  This is what search engines will see on the page and reflect in the database, while frame-capable browsers will ignore anything within a NOFRAMES element.

To make the rest of your content accessible, you should provide links to the framed pages from within the NOFRAMES element.  Remember that you're doing this not only for spiders, but also for the users of non-graphical browsers, so accompany the links with proper descriptions.  Usually, one of the frames contains a navigation bar with links to all other pages, so in the NOFRAMES element it may be enough to link to this document only.

For framed pages to be usable in the absence of frame context, remember to give them their own TITLE elements (this will improve their ranking in search engines as well).