Initialising global associative array

[Paul via Digitalmars-d-learn]

I need a globally accessible AA of type string[string] and find 
that it won't compile unless I use the static this(){} method as 
described in this thread:

http://forum.dlang.org/thread/owhfdwrpfuiehzpiuqux@forum.dlang.org#post-mailman.1522.1346449072.31962.digitalmars-d-learn:40puremagic.com

I understand the concept of this() insofar as returning a 
reference to an object but what is 'this' in the context referred 
to? A reference to the module??

It doesn't seem very intuitive (to me at least!) especially given 
that strings are immutable anyway.

Paul