Can someone point me to where the pdf documentation is for the extension
Installed version 22.214.171.124 ?
There is no specific documentation for any of the underlying extensions that provide CFML functionality beyond the CFML tags/functions they enable.
In addition, you may be able to glean the extent of the underlying feature set by reviewing the extension code itself:
Note, in most instances the extension code is just an OSGI bundling of the relevant library and doesn’t include any specific implementation detail.
I’ve just linked some more tags to the PDF category in docs