Would question about a standard be in scope on this site?
It depends on exactly what your question is, but I would say it is most likely to be on topic here if it aligns with what is on topic (process and methods, requirements, architecture, design, quality assurance, configuration management). If you are implementing a standard and have questions about writing or debugging code to do so, those kinds of questions would be off-topic and would be best asked on Stack Overflow. If you want additional resources or information, those would also be off-topic.
A question like yours about a specific OASIS standard has IMHO a certain risk of getting closed for the same reasons mentioned in this older SO meta post. However, for standards like CMIS, as it was mentioned in your question, there is a much better place where you can ask: the related Oasis mailing list.