Thank you @Christian_Reich for the explanation. It is a bit disappointing - OMOP should really try to use open vocabularies for their standard concepts. I don’t really mind that I cant use SNOMED, but what I find difficult is that users get their data aligned to OMOP (often at quite an investment), only to learn later that most of their data was aligned with SNOMED sourced OMOP standard codes, while their country does not have a SNOMED license. Maybe I am also still misunderstanding something. I work with a few communities that seek to align their data with OMOP. Everyone watches these (pretty awesome) talks by Kristin, learning about how they can group their data using OMOP - but, seems that for the most part, they are not really allowed to do many of these awesome things. Even something simple like building a Knowledge Graph with OMOP semantic relations is now not possible, or strictly speaking, I can’t even publish a Jupyter notebook that counts how many cardiovascular diseases have been reported in my cohort.