SEO Best Practices
3.1.2 Key Elements
As much as we would like to include every possible search phrase in the core structural elements, there are limits to the number of characters these elements can hold. Below is a suggested table of these limits.
||Number of Characters
*Open to discussion, some claim 874 characters
Other key elements are the heading tags H1 to H6. Note that the lower numbered heading tags have higher relevance weights. In addition, key elements include; Alternative (ALT) text in images and TITLE tag attributes in anchor text.
Bold and italicized text also carry relevance weights, however they should be used sparingly and not abusively throughout the page.