For example, take this excerpt from Wikipedia about OpenGL 4.2:
Support for shaders with atomic counters and load/store/atomic read-modify-write operations to a single level of a texture.
Does this mean that OpenGL 4.2 has guaranteed support for atomic counters, or does it just mean that starting with OpenGL 4.2 GL_ARB_shader_atomic_counters might be available on supporting hardware.
I'm also trying to figure out whether GL_ARB_robustness was made core in version 4.3. I have no interest in thing which only might be available.