Dear Geist,
In submission guidelines, magazine publishers say that they only consider unpublished manuscripts. If I post a short story on my blog, does that make it a published story?

Dear Jo,
Technically, yes. To post work online is to publish it if it is available to the public. (If it goes on a web page accessible only to teachers and students in a course, for example, a magazine editor would not consider it published.) But if your blog has modest traffic, you might submit the story to a magazine anyway, and mention this very limited publication in your cover letter.