Interesting. I checked my original source that suggested optimizing some pages for Bing and Yahoo! and the source does not provide any tips or insight on how to do it!
I checked with Bing and a quick review of the optimization recommendations indicates that they are pretty much the same as for Google. Bing does, however, recommend that you register all of your websites with Bing Webmaster Tools
. You will receive updates, access to webmaster tools and further access to recommended optimization practices.
I wasn't successful in this attempt to find specifics for Yahoo! SEO. Although, it appears that you can set up an account with Yahoo! and access their webmaster tools, too. The Yahoo! SEO tips that I did find were all very similar to what most of us do for Google SEO.
Now that I am aware of this line of SEO research, I will keep my eyes open for specifics to pass along here. What I DO know is that every search engine keeps their cards close to their chest, and they all like to make algorithm changes regularly, keeping website owners on their toes!