This Workshop concentrates on scientific metadata and their importance in maximising the utility, trustworthiness and reuse of scientific data, especially to open doors to further avenues of study, and even new scientific insight. In a more general context, 'metadata' is a vehicle for categorising, classifying and collecting data sets. This presentation will review some of the organisations that take an interest in generic metadata and interoperability between metadata specifications from different disciplines or communities. The CODATA/VAMAS Working Group on Description of Nanomaterials provides a good example of collating different specialist metadata elements in a broad interdisciplinary framework. There will be a brief discussion of the granularity mismatch between generic and specialised metadata systems.