Dynamic Tags Template
This is a Dynamic Tags, so you can find it on every Text field
Once you click on related Tag the field will appear like this:
Click on it to open his settings
A quick button bring you to admin Template section to create a new custom template to insert in this position.
If you previously generated the Template so you can easily search and select it from Template setting.
Once the Template is selected there are few setting you could use for advanced manipulation.
Post, set another Post (instead of current) for rendered contents in Template
User, set another User (instead of current logged user) for rendered user data in Template
Author, set another Author (instead of current) for rendered author data in Template
Inline CSS, render Custom CSS inline instead of separate file in footer
Show Shortcode, print the Shortcode to reuse it elsewhere with configured settings