As was pointed out, the "A" of an ABC extinguisher is for wood, paper etc, none of the portable chemical extinguishers do great with those. Water is your primary agent.
Portable extinguishers are great for quick usage especially when you don't know the source of the fire, but on the occasions that it is wood based. Throw water.
From when I taught firefighting basics. Fuels/sources of fire.
A ,,,, things that leave an Ash.
B,,,, boil, as in liquids, the only things that boil. Oil,gas,diesel.
C,,,, Current, as in electrical current.
