Bash arrays and negative subscripts, yes or no?

Question

The GNU bash manual tells me

An indexed array is created automatically if any variable is assigned to using the syntax

name[subscript]=v         


        

Answer 1

If you do man bash the section on arrays does not list this behavior. It might be something new (gnu?) in bash.

Fails for me in CentOS 6.3 (bash 4.1.2)