I'll be happy to answer that question.
Yes, they are. They have alphanumerical numbers, but there are different types of seals. There are wire seals, chain seals, high-security seals, plastic seals and paper seals. They all have unique numbers.
That might be a fault in the system that probably needs to be reassessed, which is to standardize seals or something, because the only thing we have on the manifesto—the legal paper—is the number. It doesn't say what type of seal it is.