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 piggyback off of Kittemon's answer, note that you can create mappings with null values using the alternative syntax

foo:
    << : myanchor
    bar:
    baz:

instead of the suggested syntax

foo:
    << : myanchor
    ? bar
    ? baz

Like Kittemon's suggestion, this will allow you to use references to anchors within the mapping and avoid the sequence issue. I found myself needing to do this after discovering that the Symfony Yaml component v2.4.4 doesn't recorgnize the ? bar syntax.