This is all the docs we have now:
 

"Allow a runtime class method to be initialized when a game is loaded at runtime without action from the user.
Methods marked {{[RuntimeInitializeOnLoadMethod]}} are invoked after the game has been loaded. This is after the {{Awake}} method has been invoked.

*Note:* The execution order of methods marked {{[RuntimeInitializeOnLoadMethod]}} is not guaranteed."

It does not mention the various options of callbacks

There is no info on the execution order of the callbacks.

Incorrect info:
* This is after the {{Awake}} method has been invoked.
* The execution order of methods marked {{[RuntimeInitializeOnLoadMethod]}} is not guaranteed.

The documentation was not updated when [RuntimeInitializeLoadType|https://docs.unity3d.com/ScriptReference/RuntimeInitializeLoadType.html] was added. Which is hooks that invalidates above documenation.