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.
Be sure to click on DONE and SAVE at the top.
Notice that the URL is only partially shown:
It is assumed you know the rest of the address for your blog URL.
In my case:
to create your permalink you will need to manually type in the front of your post's URL using this formula:
+ add the Permalink
Be careful about typos!