My rubbish bin [trash to some] keeps showing copies of my project every minute or so, and related to the auto backup period. Why is Dorico putting anything there in the first place? What is going on? Auto save period is 5 minutes, keep 10 copies. Weirder yet, it has only just started happening.
Dorico 3.5.12.
I assure you this is not an April Fools Day post.
Dorico hangs onto a set number of AutoSaves (for each Dorico project) in a hidden folder. Once that number is reached, it starts dropping the oldest ones into the recycle bin/trash in order that a maximum of 10 saves are retained.
Dorico also clears out the autosave folder when you close Dorico normally, or when you close a project normally, on the assumption that if you’ve saved something normally (or clicked through the prompt that you don’t want to save the file) that you no longer need the AutoSaves. In earlier versions of Dorico the deleted AutoSaves bypassed the trash entirely, and some users complained that actually they sometimes needed a way of getting these files back.
I assure you that both of these behaviours are as designed. They give you an extra bite at the cherry if everything else goes wrong.
This is fully documented in the manual in the manual’s only search result for autosave, here: Auto-save
@pianoleo All understood. So why is it throwing files into the bin every minute or so, with auto save parameters in my post? This was not happening until today, and IU changed no settings. I am working on one project, and not closing an opening it every minute. Sorry to say, I cant mark this as the solution. What is really going on? As I said, it’s plain weird.
And just now,. I see that a file is thrown in the bin every time I save. And the bin is definitely not my project save location. So I have a deterministic scenario here and generate the bin file at will. And I turned auto save off. Surely that can’t be by design? And it was not happening until this morning.
It may be that you’re confusing AutoSaves with Backups. Please read Project backups
The same general thing applies: Dorico hangs onto the specified number. If you keep saving beyond whatever the number is, Dorico keeps pushing the old backups out to make way for the new ones.
Well now that makes sense. I was indeed confused between the two. Thanks for you help.
The only nagging doubt is that I’m sure this only started happening today, but it’s entirely possible I am mistaken about this.
Having worked on computers back in the 1980’s (yes) I got used to saving all my work very frequently to cope with the periodic system crashes on the good old VAX 11/750. It has remained a lifelong habit. Any bit of work, I hit save. My own builtin auto save function. 
This is why I save every minute or so.
I’m certain that it didn’t just start happening today (or indeed yesterday). That’s the standard behaviour, and has been since version 3.5 at least. It’s done in the spirit of trying to offer as much protection as possible against you losing any data: even if you have a problem with the backup projects that Dorico creates, you should still be able to find something salvagable in your Recycle Bin/Trash.