I just noticed the new Norwegian proposal for archiving rules in the goverment list ECMA-376 / ISO/IEC 29500 (aka OOXML) as valid formats to put in long term storage. Luckily such files will only be accepted based on pre-approval from the National Archive. Allowing OOXML files to be used for long term storage might seem like a good idea as long as we forget that there are plenty of ways for a "valid" OOXML document to have content with no defined interpretation in the standard, which lead to a question and an idea.
Is there any tool to detect if a OOXML document depend on such undefined behaviour? It would be useful for the National Archive (and anyone else interested in verifying that a document is well defined) to have such tool available when considering to approve the use of OOXML. I'm aware of the officeotron OOXML validator, but do not know how complete it is nor if it will report use of undefined behaviour. Are there other similar tools available? Please send me an email if you know of any such tool.