Is there YAML syntax for sharing part of a list or map?

Question

So, I know I can do something like this:

sitelist: &sites
  - www.foo.com
  - www.bar.com

anotherlist: *sites

And have sitelist<

Answer 1

To clarify something from the two answers here, this is not supported directly in YAML for lists (but it is supported for dictionaries, see kittemon's answer).