The MSR WhisperLite Internationale stove's manual says:

"The WhisperLite Internationale™ burns a variety of fuels by using two interchangeable Jets.

1. The IG Jet is used for White Gas and Unleaded Auto Gas. This Jet is preinstalled in your stove.
2. The K Jet is for Kerosene and Diesel. This Jet is included in the parts kit with your stove.
To exchange Jets, see “Cleaning the Jet and Fuel Line.”

Use MSR® SuperFuel™ (White Gas) for optimal performance. It is the highest quality fuel available for your stove. Do not use leaded fuels. Fuels other than MSR SuperFuel lead to rapid stove clogging and require more frequent Jet and Fuel Line cleanings. Also, the use of Unleaded Auto Gas may shorten stove lifespan."

My MSR Dragonfly stove's manual says the same thing, though it refers to the gas jet as the "DG jet" and the Kerosene jet as the "DK jet".