{ } are sometimes called braces or curly brackets. They designate a list or a collection.

Lists are convenient way of copying a node and its properties.

It can be a list of numbers, or a list of points or even a list of lists.

• {1,5,2,9}
• {point01,point02,point05}
• {point01,0.25,point03,1.4}
• {{1,2},{3,5},{8,11}}

This is a very powerful way to "copy" a property of a node.