Hello,
Does anyone know of a caller wait list type of solution on Samsung?
Example: when a number is on call with a customer, a second call would hear message: You are 1st in caller line, third caller: You are 2nd in line etc.

Would this even be able to do with Samsung OfficeServ?

You want an ACD packafe which supports position in queue.

The product which replaced the Samsung ACD (forgotten the name of it) could do it.
It was made by a UK company.
Don't know if it's available in your region or not.
Otherwise you're looking for a 3rd party acd product compatible with the os7000.
Down here we have a company called cytrack which developed such a product. Even had it working with the scm too.

Interesting, never heard of this before.
A customer is interested in doing this with their OS500.
Is this just a software solution, no special hardware needed?

The Samsung version used sip trunks between the system and the software. Was only sorted on os7000.
Unless you can find a 3rd party which uses sli and trk ports you're out of luck on a 500. It's too old now

Ok, thanks for all the useful information.