The thing I find craziest about PDF/A is it isn't really a format in itself, just a vague promise not to use certain features in the ensuing file. Whether any r

The thing I find craziest about PDF/A is it isn't really a format in itself, just a vague promise not to use certain features in the ensuing file. Whether any reader holds the file to that promise is something I'm quite doubtful of. Instead I suspect most readers will do their best to display anything they're handed, happily passing it through any of the hundred-or-so, possibly legacy-code-powered sub-format decoders the file author wishes - leading to a massive attack surface. From a developer's point of view, when trying to enforce that submitted files are strictly in PDF/A format, from what I can tell there isn't much more you can do than dissect the file looking for umpteen disallowed features. Is there an ISO-compliance validator to anyone's knowledge?