For networking documentation, the card might not be on the Trello board, but we’ve definitely seen the requests for from the community and are working on resources for you all. 
We are actively working on adding replication documentation, so check out our new pages out here, and keep an eye out for more soon! Also, there is a new 6-part video series over Blueprint Networking, and even though it uses Blueprints instead of C++, it covers a lot of the underlying framework and should point you in the direction of the right C++ functions to check out.