The following lines were added (+) and removed (-):
# D Region - Causes attenuation of RF signals, low frequencies are attenuated more than higher ones. # D Region - Causes attenuation of RF signals, low frequencies are attenuated more than higher ones. Daytime only. Heavy ionization only results in absorption of MF and HF signals.# E Region - HF radio signals are reflected here back towards the Earth and sometimes higher frequencies# E Region - HF radio signals are reflected here back towards the Earth and sometimes higher frequencies. Sporadic E is known for random 6-meter skip. # F Region - Most forms of skywave propagation use the normal and cyclic ionization properties of this layer# F Region - Most forms of skywave propagation use the normal and cyclic ionization properties of this layer. Dual layer during the day, single at night.