Here are the SEO Best Practices that my company uses. Perhaps it would be useful for phpBB to review common techniques and try implementing some of them.
SEO Best Practices:
1. Put key words (and phrases) in the <Title> of each page. This should normally be automated (retrieved from the Page Title) – but some projects may allow the User to specify an optional Title for each page via the Admin.
2. Put key words and phrases in the <Meta keyword/description> tags on every page. Google ignores the META Keywords, but they DO read and use the Description.
3. Ideally keywords used in the Titles should match the Description keywords, as well as content on the page, particularly <h1> and <h2> header content (see #5).
4. Repeat the same key words several times within the content/text of each page, but repeat in different areas. These key words should be the same or similar to those used in the page titles. This is really a Chris M or a Copywriter’s job.
5. Use the key words/phrases in Headings on each page (H1, H2, H3, etc.). Subject or Product Categories on a page (or the sub-page name, etc) should use a Keyword if possible, surrounded by H1 or H2 tags. These keywords should also be in the Title and Description if possible.
6. Use the key words/phrases in the anchor text/titles of links (<a href> tags). Create internal cross-links using these key words and phrases in the anchor text. So on links to other pages, ideally those links would have a Keyword as the anchor text.
7. Use the key words/phrases in Alt Tags on images. Ideally they should also match keywords used in the Titles, Description, Page Content, etc.
8. Code search-engine-friendly URLs that do not include extensive query strings. If using PHP, use mod_rewrite to allow dynamic Web pages to be found by search engines.
9. Keep as much content/text as possible toward the top of the page, and HTML/PHP code at the bottom.
10. Put at least 250 words of text on any page that should be indexed well. (This is also the task of the copywriter.)
11. Keep the page's HTML size to 100kb or less.
12. Include a Site Map which indexes every major page on the Web site. The link to the Site Map should ideally be in the top portion of the page. In addition, Google's Sitemap Protocol should be implemented for all new sites: http://google.com/webmasters/sitemaps
13. Use a "doctype" tag at the beginning of each page.