  The AMS-02 collaboration recently released cosmic-ray F/Si data of
unprecedented accuracy. Cosmic-ray (CR) fluorine is predominantly produced by
fragmentation of heavier progenitors, while silicon is mostly accelerated at
source. This ratio is thus maximally sensitive to CR propagation. We study the
compatibility of the transport parameters derived from the F/Si ratio with
those obtained from the lighter (Li,Be,B)/C ratios. We also inspect the CR
source abundance of F, one of the few elements with a high first ionisation
potential but only moderately volatile, and a potentially key element to study
the acceleration mechanism of CRs. We use the 1D diffusion model implemented in
the USINE code and perform $\chi^2$ analyses accounting for several systematic
effects (energy correlations in data, nuclear cross sections and solar
modulation uncertainties). We also take advantage of the EXFOR nuclear database
to update the F production cross sections for its most important progenitors
(identified to be 56Fe, 32S, 28Si, 27Al, 24Mg, 22Ne, and 20Ne). The transport
parameters obtained from AMS-02 F/Si data are compatible with those obtained
from AMS-02 (Li,Be,B)/C data. The combined fit of all these ratios leads to a
chi2/dof$\approx 1.1$, with $\lesssim 10\%$ adjustments of the B and F
production cross sections (the latter are based on very few nuclear data
points, and would strongly benefit from new measurements). The F/Si ratio is
compatible with a pure secondary origin of F, with a best-fit relative source
abundance (19F/28Si)$\sim 10^{-3}$ and an upper limit of $\sim 5\times
10^{-3}$. Unfortunately, this limit is not sufficient to test global
acceleration models of CR nuclei, for which values at the level of $\sim
10^{-4}$ are required. Such levels could be attained with F/Si data of a few
percent accuracy at a few tens of TV, possibly within reach of the next
generation of CR experiments.
