systematic errors. This approach enables a straightforward and sound statistical interpretation of the models (best-fit models have $\chi^2/{\rm dof}\sim 1$), also allowing for their inter-comparison. Third, we propose a new generic propagation model (dubbed  in the following), with a number of parameters that should be sufficient to describe all key features currently present in the data. In addition to a high-rigidity break, a modification of the diffusion coefficient at low rigidity is enabled ($\lesssim 5$ GV), with two limiting cases (dubbed  and ): this allows us to assess the relative discriminating strength of the data in this energy range and to shed new light on propagation in the low-rigidity regime, where a second diffusion break might be present.

The paper is organized as follows: In , the one-dimensional (1D) propagation model and the essential physical effects involved in CR propagation are presented, before introducing our three benchmark scenarios (, , and ). In , we describe the specific iterative procedure used for the B/C analysis, and this procedure is validated and checked in two appendices: assesses the robustness of the derivation of the high-energy break, by taking advantage or not of the C and O fluxes; further discusses the dependence 