I've noticed some sites put text in the background image, example:


The text at the top "Programmer's Reference Guide" is not really text it's a background image. There doesn't seem to be any visual reason for this - it could be implemented as HTML text and at first glance I assumed it was an <h1>. On above page the <h1> is used to head sections of the page: "Naming Conventions", "Classes", "Abstract Classes", etc.

I'm guessing this is an SEO tactic, that "Programmer's Reference Guide" is going to be at the top of hundreds of pages so it's somewhat meaningless in an SEO sense, so it was made invisible and <h1>'s used for more page-pertinent things ("Naming Conventions", etc.).

Does this make sense? Is it a good practice?

Secondary issue: I was taught to only have a single <h1> per page. Is this no longer good practice?