This guide has only one goal, it should explain all core technologies of OpenCA. This is not a guide which explains how you setup OpenCA or what you have to do if your OpenCA installation doesn't work but this guide is a good source to understand the software design of OpenCA.
So if you think there is a core part of OpenCA and you don't understand why it is implemented in this way then it is a good idea to read this guide or to write a new section if you think it should be documented.