Chris Bratlien

Allows you to publish content during dev phase without having to go back and 
fix your content’s static URLs when you switch to the production URL. Registers [url] shortcode 
with your site’s base URL setting. Replaces occurances of http://mysite.com/the/link 
with [url]/the/link inside the content editor when you hit Publish or Update.
http://chrisbratlien.com/2010/05/16/relative-site-url-on-content-save/

Relative Site URL on Content Save

Allows you to publish content during dev phase without having to go back and fix your content's static URLs when you switch to the production URL …

w3prodigy

Displays information about your blog in a page or post. [bloginfo show=”url”] where show can equal any values from https://codex.wordpress.org/Function_Reference/get_bloginfo

Bloginfo Shortcode

Displays information about your blog in a page or post.

Relative Site URL on Content Save vs Bloginfo Shortcode