Linker scripts

In order to improve RPM dependency generation, I'm proposing that the 
Fedora project more actively encourage library developers to use 
versioned symbols.

In reviewing the documentation, I've realized that there is an option 
whose implications I'm not sure I understand. The GNU Linker manual 
(https://sourceware.org/binutils/docs-2.38/ld.pdf) provides an example 
on paged numbered 84:

VERS_1.2 {
  foo2;
} VERS_1.1;

And it describes that node as, "the version script defines node 
‘VERS_1.2’. This node depends upon ‘VERS_1.1’."

What is the practical difference between that and a node that does not 
depend on VERS_1.1? as in:

VERS_1.2 {
  foo2;
};

What does "depends upon" mean in this context? If there is a difference 
in the resulting shared library, I don't see it.