Before we get into it, let’s setup the nomeclature so we can discuss it without confusion.
EOTF - The electro-optical transfer function of your (hopefully calibrated) display, typically defined by BT.1886 for normal HD displays.
HLG - The Hybrid Log-Gamma Standard. Maximum peak luminance of 5000 nits
Nits - A shorthand term for light output, measured in candelas per metre squared (cd/m²).
SDR - Standard Dynamic Range (independent of resolution, e.g. SDR 1080P, SDR UHD, SDR 4K). As a delivery format this is usually DVD or Blu-ray in Rec.709 where your peak luminance is 100 nits (ST.2080-1 standard).
HDR - video created to be displayed delivering much, much higher peak white levels(4000 nits on the Dolby Pulsar reference monitor, vs the 100 nits of SDR!) That is, instead of SDR’s BT.1886 EOTF, HDR uses an EOTF that’s described by either HLG or by the ST.2084 standards. There is no resolution or colourspace requirement for HDR, but typically P3 is being used, and once displays improve it will likely switch to Rec.2020. For delivery, at least 10bits is required, and masterin requires 12bits so the colour gamut is vastly improved over SDR.
DaVinci Resolve 12.5 can currently support 3 flavours of HDR: HLG, Dolby Vision and HDR10 using ST.2084. You can play with this via LUTs, but the best way is use Resolve Colour Management in your project settings. However if you want to play with Dolby Vision you will need the CMU hardware from Dolby themselves, so that is not all that likely for anyone on these boards, but I can go into how it works if anyone is interested.
Everyone else will be using SMPTE ST.2084, or HLG. They don’t require any licensing fees or special equipment other than a HDR monitor for doing your grading and setting resolve to the correct settings.
I will write more later when I have time, but I do want to say, once you have seen a good HDR TV or projector, you will never want to watch a normal display again. Even the most non-videophile person can see the difference instantly, it is way, way more impressive than the jump from 1080P to UHD, or even from DVD to BD.