'Recycle Bin' cleaning?

NASNoob wrote:

For the past 2 years I have asked for links/docs/experts explaining the 'HOW' the ReadyNAS Recycle Bin logic works; the WHEN the logic works, so that I can understand the 'HOW' to customize my shares. I wait still. Now, perhaps this internal logic is proprietary to ReadyNAS. Fine. I gave up asking; even though 'magically' I have seen this logic work. Yes, perhaps my settings are at fault; I accept this, but I am using the default setting ReadyNAS gives me - and then fails to explain to me how to use the 2 metrics you cite. I have found zero 'help' from ReadyNAS to explain the 'days' or 'filesize' metrics given since ~2006 when I installed my 1st ReadyNAS DUO.

It's fully explained in the user's manual:

The CIFS protocol offers a Recycle Bin. This allows for a grace period during which users can retrieve deleted files from the Recycle Bin.
When the Recycling Bin is enabled, deleted files are placed in the Recycle Bin for a period of time before being permanently deleted when the share is accessed using CIFS. Files deleted when accessed using other protocols are deleted immediately. ....

Enter the maximum number of days to keep files in the Remove files older than field.
Files that are older than the value you specify here are permanently deleted.

Enter a size limit (in megabytes) for the Recycle Bin in the Limit Recycle Bin to field.
When the Recycle Bin exceeds this limit, files are deleted, beginning with the oldest first, until the Recycle Bin no longer exceeds this limit.

NASNoob wrote:
It seems to me that during any 'backup' operation any directory inside any share labeled 'Recycle Bin' should be left alone and NEVER moved.

Well, naturally you wouldn't want to backup your Recycle Bin -- you don't even want the bin in the first place. But many people desire the "undo" capability that the Recycle Bin offers, so the files in their Recycle Bins are always potentially valuable and they would want their Recycle Bin directories to be backed up along with all their other data. Therefore it would be inappropriate for backup software to always exclude that directory.