The challenges involving standardized representations of moleculesboth for small compounds and larger moleculesare well-known in the chemoinformatics community. Reaction data elevate these challenges to another level. Many reactions are being described comprising three molecules: two reactants and the product. However, other data included with reactions can have very different types. In fact, the different reaction data "stakeholders" such as chemoinformaticians, synthetic chemists, theoretical and computational chemists, ELN users and designers, developers of Computer-Aided Synthesis Design software, publishers, reaction database providers, patent lawyers, regulatory agencies such as FDA, etc. may each have a different idea what a "reaction" is. Documents and data sets used in these specific contexts typically handle this wealth of information in a way, i.e. using a specific reaction data format, that is targeted at the local needs of the software or organization, thus is neither comprehensive for all possible needs nor optimally designed for general data exchange. We have therefore previously pointed out the need for comprehensive handling of reaction data. The idea of standardized data format is that many points of view and purposes are represented and can relate to each other, without an insistence on details some just do not care about, and without inhibiting others to express all the details they do care about. We should want a format that support the full life cycle without barriers from R&D experiment, publications, patents, documentation and control of the production process, regulatory applications, quality monitoring, to trade and logistics; all types of reactions including tautomeric interconversions, catabolic reactions and chemical degradation; reactions executed in the hood or synthetic machinery as well as in living systems including entire reaction pathways; descriptive and prescriptive reaction information; single-step and multi-step reactions; and the "mood" of the reaction, such as whether it was successfully executed, attempted but failed, or a computer-aided prediction.