I had earned my highest skill in Halo 4 and Team Slayer was temporarily removed from the game and then brought back. I lost my 50 because of this and I want it back. I was so proud of it and to have it taken away was just disheartening.
The CRS ranks in Halo 4 do not work the same as they did in Halo 3. If a playlist is removed or you rank down, then the CSR changes accordingly. You do not stay at the highest rank you earn like in Halo 3. None of the CSR ranks in Halo 4 are permanently to the highest rank you reach in whatever playlist you earn it.
Hi Death by Mint,
The Halo 4 Service Record only shows your current highest CSR and not the highest ever achieved.