Given a foliation F of a closed
3-manifold and a Smale flow ϕ transverse to F, we associate a “simplest” branched
surface with the pair (F,ϕ), which is unique up to two combinatorial moves. We
show that all branched surfaces constructed from F and ϕ can be obtained
from the simplest model by applying a finite sequence of these moves chosen
so that each intermediate branched surface also carries F. This is used to
partition foliations transverse to the same flow into countably many equivalence
classes.