| passIndex | The index of the pass. | 
| tagName | The name of the tag. | 
Searches for the tag specified by tagName on the shader's active SubShader and returns the value of the tag.
| subshaderIndex | The index of the SubShader. | 
| passIndex | The index of the pass. | 
| tagName | The name of the tag. | 
Searches for the tag specified by tagName on the SubShader specified by subshaderIndex and returns the value of the tag.