The Block documentation provides a description for each block available in Phratch. It is possible to update or write documentation for new blocks, directly inside Phratch.
The documentation is based on the first comment of each block. So, when you are in developer mode, go in a block source code, you will see the first comment line, which is the description of the block. Then, go inside Phratch and shift-click on the file menu. Click on the entry “Generate HTML documentation”. This will create the image repository and the html page for the documentation.
As I am the sole administrator, If you want to update the current doc, you can send me the generated files (they are available just near the file pharo.image, in Phratch repository).
This process can help you to generate your own documentation, on your own block.