Calls continue for agreed standards for taxonomic literature. Earlier work identified three key levels: microcitations, metadata and content. Broad agreement has been reached on the first of these, although the standard needs finalisation, including a decision on LSIDs. A standard for metadata is still to be agreed, and must accommodate both librarian and taxonomist needs; this is becoming urgent with the development of the Biodiversity Heritage Library (BHL) and the need to access its content. The most complex standard is for complete taxonomic literature content. Taxonomic literature accommodates many different data and information types, including those subject to existing TDWG standards. This raises the possibility of it serving as a test bed for full interoperability of taxonomic data and linking of TDWG standards. However, expression of such data and information in literature sources often differs from the source material examined by other TDWG groups. In developing a standard the requirements of meeting several goals interact: a) interoperability across data and information types; b) maximising cost-effective access to and display of information and data in a manner for the user; c) cost-effective mark-up in agreed formats. Alternative routes to interoperability include a) making different schemas congruent while reflecting properties of the data sources, and b) embedding different modular schemas within a larger container. The degree of atomisation of the content will impact both on the breadth of user needs that can be met cost-effectively, and issues of mark-up. Once interoperability is achieved, user-friendly navigation tools for the information universe thus created, and delivery of output and choices expected by different users, become issues that must be addressed.