Limited Editions are, well, limited in production run to only a small batch. Only that amount is ever produced of that exact variant of the item is never produced again.
Additionally, LE items are individually stamped with a unique number (pins are engraved on the back) indicating which individual one you own from the print run (a LE of 50 means they would be numbered 1/50, 2/50, etc).
Limited Edition releases ensure you own a completely unique item!
I typically offer Limited Edition items (pins) through Kickstarter campaigns.
When I run a pin campaign on Kickstarter, I get a specific count of exactly how many LE pins need to be made. But, as you might guess, sometimes things come up and backers cancel, change their mind etc. and I end up with leftovers. Lucky for you!
Kickstarter project backers who purchase full sets do get matching numbers, but any LE pins listed on my shop are leftovers, and as such will not have matching numbers. You will get a random number from the print run for each pin.
Probably not. I just word it like that on the off chance I decide to bring back something old again (for some reason), but please consider retired items to be discontinued. This is to contrast with Limited Edition items which NEVER will restock to respect the intentional limited run.
That said, I sometimes find extras of sold out items in my storage room and put those up, but it's rare.
If you're looking for something that's sold out you can try asking on my Discord server in the Pin Trade channel where you're welcome to buy / sell / and trade with other collectors.