Are "GL_EXT_secondary_color" & "GL_EXT_texture_env_combine" compatible?

OpenGL OpenGL: Advanced Coding
1

I have received conflicting feedback about whether the secondary color array can be specified by the texture combiner extension. Is this possible, and how is it done?

Thank you.

2

They are compatible.
If you are asking if you can specify the secondary color in your tex combine code, then I think the answer is no.
Look at page 189 (203 in Adobe Reader) of the GL 2.1 spec.
No way to specify the secondary color.