What do the leading four digits mean?

It is just the way the server keeps track of different documents that are posted on it. When you post a file, it gets numbered. I am not entirely certain of this, but I think this helps prevent problems arising from files that are posted with the same name. 

Thank you.

When you post a file, it gets numbered. I am not entirely certain of this, but I think this helps prevent problems arising from files that are posted with the same name. 

I have run across several files that have different titles but the exact same four digit file numbers.

Thanks for this. I have wondered the same. So I assume then, when a newer version of the same text is posted the number will reflect that?

I have run across several files that have different titles but the exact same four digit file numbers.

Were these all current, that is, not files that have been removed or reposted?

I have run across several files that have different titles but the exact same four digit file numbers.

Were these all current, that is, not files that have been removed or reposted?