  The Characterisation data model is a standard of the International Virtual
Observatory Alliance (IVOA) that describes observational datasets in the
multi-dimensional parameter space. Defining three properties: coverage,
resolution, and sampling along different physical axes (e.g. spatial, spectral,
flux) with variable level of details for the description, this model has been
used in several IVOA contexts: Simple Spectral Access Protocol, Spectrum Data
Model, ObsTAP (Table Access Protocol for the Core Components of the Observation
Data Model. Here we propose a new version which addresses more completely the
most detailed level of description (level 4) dealing with variation maps of
coverage, resolution, and sampling. It also introduces new specific axes in
order to cover various photometric measurements, velocity and polarimetry.
Special care is given for composed data sets. These improvements and add-ons
follow the evolution of needs expressed to the uptake of VO tools in various
observation domains for data discovery but also for data analysis requirements.
This is also introduced to tackle use-cases designed to analyse scientifically
datasets in the V0 context together with calibration/provenance information.
