Let's look at a scenario, which, incidentally, happened to me, today. I was re-hashing and editing - in a frenzy of activity, which even surprised me.
I saw a range of published posts, I had done, way back in 2006, which I thought needed to be re-done. WRONG! Update them, yes, but don't try to re-do an existing post, by re-newing it, and using the same URL. It won't happen! Blogger won't let it happen!
You can't use the same URL - again. Blogger will add a suffix to the existing URL, to prevent this.
Eg: One of the URLs I wanted to use again was the 'now deleted' -
I copied some of the contents over to a New Post. I completed the post, and published it. The new post URL was (now deleted, also) -
See the difference? Blogger has added a suffix (_7288). Now, I don't know if these suffixes have any specific meaning. I've actually seen a few during my days with Blogger. Some bloggers either aren't aware of it, or don't care, or just ignore it, because they think that's normal? Who knows?
I noticed as soon as I went to copy the URL for my blog Index. Of course, I immediately tried again. Different result, though. Remember this if you see a URL like this:
When I don't know something, I try to find out - then, as a last resort, I turn to Nitecruzr 1, and The Real Blogger Status blog (my blogging bible, so to speak). He directed me to a post written back in August, 2009, in which he explains this exact phenomenon. Chuck explains about the URLs and how they are constructed, and what happens if bloggers try to do as I did. No worries, though. It's not going to explode your computer, or wipe your blog off the Internet.
So, what did I do to fix the situation? I once again, copied the contents, which is exactly how I wanted the post to look, and this time, when I clicked on New Post, I changed the name (Post Title) - so that Blogger would issue a new URL, and would not think I was trying to re-use the same, old, URL, which I deleted.
I got a new URL, and my post is looking good!