What is HDF LCD?

Hi,

Our company has purchased some Latitude E6530 notebooks. The systems were ordered with HD LCDs. However, when I put the tag on the Dell support site and check the configuration it shows "Liquid Crystal Display, 15.6HDF, White Light Emitted Diode, AG, Legend". I know for a fact that these are not Full HD LCDs because the max resolution supported is 1366 x 768. So what is HDF?

We also have a previous order with HD+ LCDs which show up as HDF+ on the site. Obviously the 'F' has some meaning but I'm unable to figure our what it is.