You will be creating the equivalent of a third party unlisted modpack so you only need to be looking at C and D. The colour of these columns denotes the type of permission and the content links you to the appropriate pages
Wow, that's an edit.
Ok, so we are looking at the public permissions columns. But C and D have different contents, yet only one header for column C -- how does C differ from D, and when do we have to worry about the differences.