iRule question: What does "switch -glob" do?

We have an issue where one server's getting traffic where another isn't when this iRule directs it to the 8081 pool (has two servers in it). Does anyone know what the "switch -glob" part of it does? I've never seen that before.

when HTTP_REQUEST {

 switch -glob [HTTP::uri] {

 "/ssomanager*" {

  pool prod-8081-pl

Thanks!