ASRock's OSD system is split into six tabs, which you can see here:
The OSD itself is fine overall, it's very easy to navigate with the joystick and ASRock has included a fair selection of features. That said, I don't like that there's no way to customise quick shortcuts via the joystick, and there's a worryingly small amount of anti-burn in features too. Some of the settings are also slightly confusing, given there's an sRGB mode in ‘Image Setup', but it doesn't actually clamp the gamut unless you also adjust the ‘Color Space' option which is found in the ‘Picture' sub-menu. I think you can tell ASRock is still relatively new to the monitor space as there is room for streamlining here.