I've just started familiarizing myself with the FIT SDK after downloading the package (Release 20.24.01). One of the documents "D00001309 FIT File Types Description Rev 2.1.pdf", under Section 9.2 VIRB FIT Messages, states "For a full list of messages and fields refer to the FIT SDK". The other PDF files in the root directory do not contain any additional information on this subject. What document is this statement referring to and what folder is it located in?