Abstract: Even though it has been noted that comparative concepts for typology are merely instruments for research and may therefore differ across researchers (Haspelmath 2010), we want different databases to be comparable. For example, we would like to compare data from WALS (Haspelmath et al. 2005/2013) to be comparable with data from SAILS Online (Muysken et al.) The task is thus similar to the task of lexical comparison across languages by means of a set of comparison meanings. For the latter, a semi-standard ontology now exists: The Concepticon (List et al. 2016, concepticon.clld.org), which has over 2500 comparison meanings which bring together comparison meanings from diverse lexical databases. This allows automatic comparison of lexical forms from diverse databases- The present talk explores the possibility of a counterpart of this for grammatical comparative concepts, called Grammaticon, which would facilitate the comparison of different grammatical datasets. The goal of allowing comparability, also for machines (i.e. interoperability), is similar to that of the GOLD ontology (General Ontology for Linguistic Description, Farrar & Langendoen 2003), but the latter attempts to come up with a general set of concepts for description, which is impossible, because each language has its own system. The GOLD’s goal thus resembles the idea of Wierzbicka’s natural semantic metalanguage, which can be used to describe any language, but which has not proved practical. The Grammaticon’s goal is more modest, in that it proposes a set of highly ecumenical comparative concepts with associated terms that can be used in comparison. No claim is made that these concepts should be useful for describing individual languages. References Farrar, Scott & D. Terence Langendoen. 2003. A linguistic ontology for the Semantic Web. GLOT International 7(3). 97-100. (Available at http://www.linguistics-ontology.org/gold.html) Haspelmath, Martin. 2010. Comparative concepts and descriptive categories in crosslinguistic studies. Language 86(3). 663–687. Haspelmath, Martin, Matthew Dryer, David Gil & Bernard Comrie (eds.). 2005. The world atlas of language structures. Oxford: Oxford University Press. (2013 online version available at http://wals.info) Kortmann, Bernd & Lunkenheimer, Kerstin (eds.) 2013. The Electronic World Atlas of Varieties of English. Leipzig: Max Planck Institute for Evolutionary Anthropology. (Available at http://ewave-atlas.org) List, Johann-Mattis & Cysouw, Michael & Forkel, Robert (eds.) 2016. Concepticon. Jena: Max Planck Institute for the Science of Human History. Muysken, Pieter, Harald Hammarström, Olga Krasnoukhova, Neele Müller, Joshua Birchall, Simon van de Kerke, Loretta O'Connor, Swintha Danielsen, Rik van Gijn & George Saad. 2016. South American Indigenous Language Structures (SAILS) Online. Leipzig: Max Planck Institute for Evolutionary Anthropology. (Available at http://sails.clld.org)