One of the purposes of Stackexchange is to create a sort of library of questions, which is easily searchable.
Surely this means that when a question is closed as an exact duplicate a link should be given to the original question? (If I remember correctly, a link has to be given when flagging a question as an exact duplicate, so the link should be known!)
However, it seems that this is not so!
I first noticed this today because of the rather confusing situation that arose from this question. A somewhat obscure question about looking at $S_5$ in terms of generators and relations was closed as an exact duplicate, but no link was given. I thought it was an odd question to be a duplicate, so I wanted to find the original. However, it turns out that the question was edited after the closing to become a brand spanking new question!
So, was this question a one-off? Are links normally given on such occasions? From memory, the links are often in the comments, but this is not the case here, and is presumably not the case always.
Should something not be done about this?