Builtin shader properties (for post effects)

Hi,

Is there a list of buildin shader properties?

I've just started learning about Command Buffers with RenderingCommandBuffers50b22 example. In CommandBufferBlurRefraction is used instruction Shader.PropertyToID("_ScreenCopyTexture") (also with "_Temp1" and "_Temp2" as parameter). Search results suggested that _ScreenCopyTexture is what CommandBuffer.GetTemporaryRT returns (?).

I guess that BuiltinRenderTextureType has all avaible render targets. But there's no information about how it's connected to shader properties (like _ScreenCopyTexture).
How can I find what properties are avaible out-of-the-box and which (if any) are created for the example?