Chess Informant R+2P vs. R+P

After the previous post on Reuben Fine's 'Basic Chess Endings' (BCE), Fine 1 - Tablebase ½, what's next for R+2P vs. R+P endgames? Chess Informant (CI) comes to mind with both the 'Encyclopaedia [Encyclopedia] of Chess Endings' (ECE) and the endgame section of the 'Informant' periodical.

Some years ago I discussed both products in Chess Informant Endgames (March 2012), which included a copy of the table of contents for the ECE volume on Rook endings The structure of that volume's chapter devoted to R+2P:R+P is shown below (p.162).

The short left branch ('5/a') of the upside-down tree is for endgames with no passed Pawn. The branch below it (the 'middle' branch) is for endgames where the stronger side has one passed Pawn, while the right branch shows endgames with two passed Pawns. Both of those long branches are divided into sections where the side with two Pawns has connected, disconnected, or doubled Pawns. Those sections are further divided into subsections according to the relationship with the opponent's lone Pawn. It looks simple enough, but it took me some time to understand the symbols. The same system was adopted in Informant 39 (1985H1) and thereafter.