One thing to look at with the extinguishers that come pre-installed in RVs is the Underwriters Laboratories (UL) rating found on the rating plate.
All extinguishers are rated by UL according to the class and size of the fire they are designed for. Class A and B receive a numerical rating to determine the extinguishing potential for each type and size of extinguisher. Class C is basically a class A or B fire with electricity involved. The C designation indicates a non-conductive agent.
Class A and B extinguishers rated 1-A to 40-A. 1-A equals 1 1/4 gallons of water and is the benchmark even for non-water type extinguishers. 2-A has two times the extinguishing capability of a 1-A, 10-A ten times a 1-A etc. Water extinguishers, of sufficient size and in the hands of a trained person, can put out a surprisingly large amount of Class A combustibles. I did it several times as a firefighter. But I had a 5 gallon "can" and the proper protective equipment which allowed me to be in the smoke filled environment.
Class B extinguishers are rated 1-B to 640-B. 1-B equals one square foot surface area of a liquid pool fire and is the benchmark. A 60-B extinguisher should be able to extinguish 60 square feet of flammable liquid fire by a non-expert. That's not a large size pool.
Class C extinguishers have no numerical rating, the agents are tested only to determine non- conductivity. Beware! As long as the equipment remains energized, the potential for the fire reigniting is good. De-energize the equipment and then you simply have a Class A fire.
The disposable fire extinguisher that came with my RV was rated "BC", That simply means that the extinguisher was not rated for ordinary combustible (wood, paper)items. Several reasons for that, most common one is the type of extinguishing agent.

Halon, and the new "clean agents" designed to replace them extinguish fire by interrupting the burning process, not by removing oxygen. Traditionally, to stop a fire you need to remove one side of the triangle - the ignition, the fuel or the oxygen. Halon adds a fourth dimension to fire fighting - breaking the chain reaction. It stops the fuel, the ignition and the oxygen from dancing together by chemically reacting with them."
To much information? Perhaps. But all that being said, your best chance to defend yourself from the danger of fire is to GET OUT! Once away from the hazardous situation, you can make a judgment decision to attempt to fight the fire.