YCbCr word is there for historical reasons

FFV1 can (and does) compress any YcbCr-style color space.

Author: JeromeMartinez

ffv1.md

@@ -37,7 +37,7 @@ The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "S
 
 `RGB`:   A reference to the method of storing the value of a Pixel by using three numeric values that represent Red, Green, and Blue.
 
-`YCbCr`: A reference to the method of storing the value of a Pixel by using three numeric values that represent the luma of the Pixel (Y) and the chrominance of the Pixel (Cb and Cr).
+`YCbCr`: A reference to the method of storing the value of a Pixel by using three numeric values that represent the luma of the Pixel (Y) and the chrominance of the Pixel (Cb and Cr). YCbCr word is used for historical reasons and currently references any color space relying on 1 luma and 2 chrominances e.g. YCbCr, YCgCo or ICtCp. Exact meaning of the three numeric values is provided by the container.
 
 `TBA`:   To Be Announced. Used in reference to the development of future iterations of the FFV1 specification.
 -------- --------------------------------------------------------------