As Jim says, if you have to 'shoehorn' it into an existing type, then do.
But for my part, I think any classification is a rather strange one if it doesn't allow for any Policy. (But yes, I DO understand that changing an embedded system could be difficult! You could probably argue for several different types - I'd be inclined toward a 'specification' on the grounds that it 'specifies' what should be done at a very high level, but I"m sure there's other points of view.
I wouldn't spend a lot of time worrying about it - and no, you definitely don't have to give it a number or a code or anything like that.
To take a leaf out of Randy's book, you could even call it 'Jack & Jill Go up the Hill' and make it a 'form' type, provided the
content has what is required. Though I wouldn't recommend this approach & it might take a little bit of explaining to your people & your auditor if you did though
