Documentation/specification for custom Url scheme

I’ve tried to find any documentation or specification for custom URL scheme, and my search hasn’t returned anything ;(
While looking through forum, I’ve bumped across parts of the scheme like x-Devonthink://createText, x-Devonthink://createBookmark and so on.
Where can I find all the available parameters for the scheme? I need it to integrate DTTG with Workflow app in Ios.
Thanks for help!