It is used as a reference for the location of other things.
It was used as a reference for later writers of the show.
It is more fun to go to the movie and learn the lines from the people, perhaps using this as a reference.
Below is a list that can be used as a reference.
This page is about the measurement using water as a reference.
This work is being used as a reference by scholars and students.
Often used as a reference in the commercial laptop industry.
This technology used as a reference for many studios still today.
This is a book to be read, used as a reference and consulted often.
The term itself is likely to only be used as a reference to a group of selling points.