Asian Leopard Cats
The F refers to Foundation Generation, or Filial. This indicated the number of crosses between ALC & Domestic. The F number is used for quick reference.
F1 - Is the 1st generation cross, meaning one parent is an ALC with 50% or higher wild blood
F2 - Is the 2nd generation there will be a grandparent who is an ALC
F3 - Is the 3rd generation
F4 - Is the last generation before a cat is recognised as a true Bengal