Imaging subset extension on NV&ATI

I’m a bit confused about this “extension”. Here

You can determine if an OpenGL 1.2 implementation implements the imaging subset by checking the result of glGetStringGL_EXTENSIONS(GL_EXTENSIONS) for the substring ``ARB_imaging’'.

but both NV and ATI cards has the substring “GL_ARB_imaging” instead of “ARB_imaging”.
My 3DLabs card has the token “ARB_imaging” so, who are right, NV&ATI or 3DLabs?
This caused me some problems, for example I’m using glew for extensions management (but are giving me too much troubles, there are problems with GLSL extensions too…), and glew searchs for “GL_ARB_imaging” so it can’t detect the imaging subset of my card.
I fixed it searching for both tokens, but I want know who are right.

By all standards and conventions used in GL it ought to be GL_ARB_imaging. But if indeed 3dlabs cards use only ARB_imaging, it’s best to check for both as a workaround.