Mapping the content of one ELN to another -even when covering only parts of interest in a certain data exchange scenario -can be a complex task, as ELNs may have different data structures that may prevent options of a one-to-one mapping of content. Also, the granularity of descriptions referring to certain ELN entities may be quite different, depending on the focus of the ELN's application and use-cases. As a result, one ELN may have a certain set of information stored in well-defined database tables with values therein most likely correlated to standardised units, whereas the same information is given in textual form in the other ELN. In the worst case, one ELN stores information that is neglected in the other and vice versa.