Wildcard

You can just use 'else' at the bottom to set a default action for any requests that don't match the first conditions:

if { condition1 }{
   do something
}
elseif { condition2 }{
   do something else
}
elseif { condition3 }{
   do something
}
else {
   do a default action
}

You could also use switch to do this, but I think the if/elseif/else structure is a little more efficient. You can check the iRules wiki for switch for more info on this.

Aaron