We propose a general solution in terms of a universal and simple XML-based language (SignalML) for meta-description of existing formats. Using this metainformation, we may adopt any software to work with the original datasets, just as easily as e.g. programming a ``classical" import unit for a new format. This eliminates the need for conversions and multiplying the data.
Definition of SignalML includes a universal and flexible schema for defining and creating arbitrary annotations (tags), which can be uniquely (secured by checksums) related to any arbitrary point or epoch of any channel(s) of the recording. These definitions can include e.g. the traditional hypnograms, artifact tags, arbitrary textual annotations related to any instant of the recording or exact markings of start, end and channel of transients.