What tags/coding are not good for SEO?

[JordanBrown]

what tags/coding are not good for SEO? and also what tags not to include while creating website.

For example -  I read some where to avoid Span tag.

[Martijn_Scheijbeler]

Hi Jordan,

I would only stay away from tags related to frames and iframes as they're not good for SEO. Besides that you'll be OK with every kind of tag. Including the span tag. It's ridiculous that somebody would argue that using these tags are not good for SEO as they provide a lot of opportunity to style elements within an element.