Heavily vs Lightly obscured

[BobTheNob]

Quick question. Whats the diff between light vs Heavily obscured? I was checking PHB (dont have errata or HOFTL on hand) and I couldnt see a mechanical difference.

 

[Colmarr]

Light obscurement (?) grants concealment.

Heavy obscurement grants concealment if the target is adjacent to you, or total concealment if it is not.

 

[barbiomalefico]

# Lightly Obscured: ranged and melee attacks get a -2 malus to hit a creature lightly obscured.
# Heavily Obscured: ranged and melee attacks get a -5 malus to hit a creature Heavily obscured unless the attaker is adjacent in that case the penality became -2.
# Total Obscured: ranged and melee attacks get a -5 malus to hit a creature Total Obscured

Defender Lightly obscured, attacker gets a -2 to hit;
Defender Heavily obscured, attacker gets a -5 to hit or a -2 depending on the square where he attack.
Defender Total obscured, attacker gets a -5 to hit