Your Blogger blog uses two different yet related HTML / XML templates , in formatting and displaying your posts. The blog template defines objects that are consistent for the entire blog - and the post template defines objects that are consistent for each post (though the content of each post will vary, from post to post). You can change the blog tempate, when you wish. The post template , when the blog is published, becomes part of the blog template - but the two are maintained separately. This lets you change your blog template (and the page layout) without affecting the post template (and the posts layout), and vice versa. When Blogger makes changes to post related features, they change post template code.
What Blogger won't tell you