https://github.com/cplusplus/reflection-ts is the repository for the C++ Technical Specification "Extensions for Reflection".
The draft Technical Specification is found in the src directory and is written in LaTeX. There is a Makefile that can be used to compile the sources, or you can use the latexmk program e.g. latexmk -pdf ts will generate a PDF.
The latest version of the draft can be viewed online at http://cplusplus.github.io/reflection-ts/draft.pdf