The participation type is not visible because promo codes limit access to the corresponding participation type by hiding it from any constituents who did not arrive to the event site using a URL with the promo code in it. The promo code can be added to the URL using the following URL argument:
&s_promoCode=

For example, if you have the following settings:
  • TeamRaiser URL: http://site.convio.net/site/TR?fr_id=9408&pg=entry
  • Participation Type: Volunteers
  • Promo Code: volunteer
The "Volunteers" participation type will not be visible unless a constituent uses the following URL to get to the TeamRaiser site:
http://site.convio.net/site/TR?fr_id=9408&pg=entry&s_promoCode=volunteer

You will want to distribute the URL to any participant who will need to use the promo code to ensure they can properly register for the participation type.