NamUs question

I have a question about NamUs that I’ve wondered about for a long time and I wonder if someone who reads this blog can answer for me:

When you search for something on NamUs — say, the first name “Sharon” — and come up with a list of results, and click on one of the cases on the list, it has two numbers at the end of the URL. One, I think, is the actual case number, which never seems to change. Sharon Kay Leinart (missing from Tennessee since 2013), for example, has the number 20176. But after that case number is a / symbol and another number. Like, I just searched for the first name “Sharon” and clicked on Sharon Leinart’s case among the results, and it lists the second number as 22. So her entire URL (as I write this; I’ll get to that in a moment) is https://www.findthemissing.org/en/cases/20176/22.

It seems to make no difference what the second number is: if you change that number to 23, or 21, or 1985, the MP you come up with is still Sharon Leinart. And if you remove the second number altogether, it also makes no difference: the URLs https://www.findthemissing.org/en/cases/20176 or https://www.findthemissing.org/en/cases/20176/ still produce Sharon Leinart and no other person.

The second number also seems to be different every time I search. I have learned to remove the second number when I bookmark NamUs cases for my “to add” folder, because otherwise, https://www.findthemissing.org/en/cases/20176/23 and https://www.findthemissing.org/en/cases/20176/22 or https://www.findthemissing.org/en/cases/20176/anyothernumber come up as separate bookmarks when they all point to the same MP. My bookmark for Sharon Leinart is therefore https://www.findthemissing.org/en/cases/20176.

My questions

  1. What does that second number mean?
  2. Why does it change every time you perform a search for that person?
  3. Why is there at all, since it’s not necessary for people to see the casefile?

This is not a big deal, it’s just a curiosity of mine. Can anyone familiar with the workings of the NamUs database, or computer databases in general, enlighten me?