A problem I don't know if I can ever fix

When I read this prompt and understood "seal" I was thinking of the seal that authenticated its sender, sealed the letter, and guaranteed that the letter had not been opened. So when I read this I thought "So the seals that authenticated a document of special importance were never opened? That doesn't make any sense." I had to stare at this question for a few seconds after taking the timed section and seeing I got it wrong to understand the seal they were talking about was placed on the document like a stamp and not like a seal as in "sealing the letter shut." I think the prompt saying the important documents used a seal twice, one as a stamp of authentication, and one to seal the document shut. But I would guess the seal that seals the document would also be a sign of authenticity. I honestly have no idea how I can get better at resolving ambiguity in the prompt. And I also really don't think I understand how the prompt is describing the different use of seals.