While the previous page covered "good acceptable politically correct deeds" this page covers methods that may be referred to as "tricking the search engines" - that is - getting a better indexing than the content itself could justify.
GRAY TRICK 1 : KEYWORDS AS COMMENTS
Robot says: If the designer writes a keyword in an HTML comment, it is most likely describing for the content that follows.
Therefore: You might benefit from writing keywords here and there in your HTML source - not that it's descriptive at all for what the codes are REALLY about - but the robots will think they are ;o)
GRAY TRICK 2 : KEYWORD CLOAKING
Cloaking is a technique where the page that the search engine sees is different from the page that the user will see. This is quite a complex matter, and there are several approaches based on different technologies.
Some sites scan the IP address of visitors, and if the address is found in their collection of search engines, the content is immediately changed so that the search engine scans different pages than are actually hosted on the site when a normal user visits.
CLOAK CONTENT GOES HERE!
GRAY TRICK 3 : ADVERTISE POPULARITY
It was mentioned previously that robots such as Google.Com rate their results based on link popularity.
Therefore: If you see a page that links to your site, why not spend a minute on submitting the page to relevant engines? Your site may be half as popular as many competitors because 90% of the links pointing to them may be unknown to the robots. However, if you make sure that 100% of your sites popularity is actually known by the robots, then you may get listed before the more popular competitors. (Some sites have automated link sniffers, that automatically submit pages to selected engines whenever they find a new link pointing to them.)