gazfan

As far as I know retention works as if there is a bucket for each group.

Each bucket has a limited size, but some fill up faster than others.

If you choose files from a bucket (group) with minimal traffic you may stand more chance of finding older posts.

Files from a group with heavy traffic (high numbers of large files) will be constantly running out of capacity (overflowing) & each new file posted will always displace an older one.

Files from text groups will usually have much longer retention than files from binary groups, simply because they tend to be smaller.