...
The field is called 'VF' for Vegetation Fractions even though it also contains ocean, glaciers, and lakes. The following is a table of GEM input vegetation fractions and corresponding roughness lengths. For CLASS the roughness length is the height of the vegetation divided by 10.
In the geophysical fields the variable is called 'VF' but in model output it is called '2V'.
Instead of having one field name for each surface (vegetation) fraction it was decided to use the same name, 'VF', but different levels to distinguish the different types. The fields themselves contain the fraction of the specific type.
...