Matches 0 or more characters within a topic level

For example orders/*gin*

would match sends to

• orders/gin
• orders/begin
• orders/ginseng
• orders/beginning

But not

• orders
• orders/in

Matches multiple topic levels and may only be used as the last leve level in a topic filter strings

For example orders/...

would match sends to

• orders/events/MSFT
• orders/updates/APPL
• orders/cancels/US/IBM
  

But not

• orders
• order-updates