Split Ticket is a feature that allows you to take a ticket and split it into two after any post within that ticket. This is a useful feature when you consider that your end user may be using a previous ticket email confirmation to add posts until the ticket becomes an enormous to the point where it is no longer manageable. If you merge two tickets and need to split them then this is also how you would want to do it. You can split a ticket at any point in the ticket after the initial post.
This option can be found on the upper right hand corner of the ticket.
Once you click on split ticket a new ticket will be created along with a new ticket id.