TCDL usage document: what is its purpose?

Hi

I just started creating my first TCDL file. I have several questions and
will break up my questions into several emails to make it easier address
them.

So far the usage document is not too helpful. What exactly is the main goal
of the usage document? Is it a reference for TCDL language or a "how to"
document?

Under section "Terms and Definitions" the links to WCAG 2 and W3C QA  Voc.
do not work. I assume some of the more obvious errors are known (e.g. level
"1" on every section).

Thanks
Shane Anderson
WebAIM.org