The following information is per Google Forum Help April 7-2014.
Google's Blogger has made changes in the feature "LINKS" shown on the right side of the "Compose/Draft" page of your blogs.
In the past, if a specific URL was needed (perhaps for a blog hop), it was easy to copy and paste the link from the LINK and PERMALINK feature.
This has now been "abbreviated".
Click on LINKS. The option for either "Automatic" or "Custom" is presented.
Actually, it is easier using custom. Choose one word. Even if you change your blog title, the Custom Permalink will remain the same. However, with Automatic, if the title of your blog post changes even by one space or word, your Permalink will automatically be reconfigured to match it.