How do I add CONFIRMATIONTOKEN url paremeter to a custom 'create new case' link?

I am trying to setup a custom case record type selection page. I have a record type query in my controller, and I have a link to the 'new case page with specific record type' in my page. I create a case using the standard record type selection page and I examined the url to use as the link in my page.

The link in my page is working correctly to take me to create a new case with the correct record type, and save or cancel.

I am not sure if there is a problem because there is this url parameter called "CONFIRMATIONTOKEN" when i create the case using the standard record type selection page, which I am not able to reproduct in my custom 'create new case' link.

Anyone know what the confirmation token url paremeter is used for or how to replicate it?

Also is there a better way to go about creating a custom case record type selection page?

Thank you.

Controller:

public class rtController { List<RecordType> recordType; public List<RecordType> getRecordType() { if(recordtype == null) recordtype = [Select r.SystemModstamp, r.SobjectType, r.NamespacePrefix, r.Name, r.LastModifiedDate, r.LastModifiedById, r.IsActive, r.Id, r.DeveloperName, r.Description, r.CreatedDate, r.CreatedById, r.BusinessProcessId From RecordType r where SobjectType = 'Case' ]; return recordType; }}

Page:

<apex:page controller="rtController" tabStyle="Case" showHeader="false" sidebar="false"><apex:sectionHeader title="Case" subtitle="Record Types" /> <apex:pageBlock > <apex:pageBlockTable value="{!RecordType}" var="rt"> <apex:column > <apex:outputLink value="/500/e?retURL=%2F500%2Fo&RecordType={!rt.Id}&cancelURL=%2F500%2Fo&ent=Case" > {!rt.name} </apex:outputLink> </apex:column> </apex:pageBlockTable> </apex:pageBlock></apex:page>