The code formatting button gets abused a lot. People use it to emphasize text (example) or highlight tech and product names (examples: 1, 2). You see it both in original posts and in the edit queue.
Can anyone think of a way how people could be informed about the correct use of code formatting? I often leave a comment after correcting the post and usually people take it well. It seems like the problem is that people just don't know that formatting option should be used for code only.
It's hard to detect automatically if the formatting is applied to non-code, but perhaps an unobtrusive "Is that really code?" info box could appear when there are only a-z letters in formatted parts.
As an aside, I wonder if this is a cultural thing, since it seems that people who do this are often from Asia judging by their names. Are there writing systems where monotype is a common way to highlight text?
<code>
instead, maybe that'd have them notice something odd about the semantics.