FAQ 72 contains a list of tags that can be used in entries.
<div> is present but
<span> is not. While the list does say that "some others that are not included here" are also allowed, "div" and "span" kind of go together for me (since they're both essentially semantically empty containers, for block-level and inline content, respectively), so they should both be in there IMO.
"span" would go between "small" and "strike".