Is it common practice to put keywords in html markup for SEO?

Though it's on the edge of programming questions, I 开发者_Go百科think this is still relevant here, as only those of us actually doing the coding for a site would be considering this.

I've been reading more about keyword placement, and it seems to me like a good place to do keyword placement would be in the class and id names chosen for the elements they are representing. I'm not talking about any kind of black-hat keyword stuffing thing but real legitimate use of descriptive keywords for elements.

Is this something that is actively done for SEO?

Nope.

Search engines might look for microdata / microformats / rich snippets, but that doesn't mean they are actively scanning every classname and/or ID.

Content is KING!

Hire a good writer and give them a list of keywords that you feel are important to the Client/you, that would be your best bet. What your talking about might be crossing the line to blackhat SEO. Not to sure how deep search engines drill down into the code though so it might be just a waist of time.