"Unsupported" shader showing in log, but it still works fine?

I'm using a double sided shader for the hair on my characters (see shader code below).

The shader works fine and does what it's supposed to do, but when I view the output log from an actual standalone build, I see the following line everywhere the hair is loaded:

"Unsupported: Transparent/Cutout/Diffuse Two Sided"

Is this something I should be concerned with? Like I say, the shader appears fine, but I don't want problems down the line and I hate to have unsolved issues in my release build.

The error doesn't show up while running in the editor, just in the standalone build.

Here is the shader code it's referring to:

 Shader "Transparent/Cutout/Two Sided Hair" {
     Properties {
         _Color ("Main Color", Color) = (1,1,1,1)
         _MainTex ("Base (RGB) Trans (A)", 2D) = "white" {}
         _Cutoff ("Alpha cutoff", Range(0,1)) = 0.5
     }
     
     SubShader {
         UsePass "Transparent/Cutout/DiffuseBack/FORWARD"
       UsePass "Transparent/Cutout/Diffuse/FORWARD"
     }
     
     Fallback "Transparent/Cutout/VertexLit"
 }