what is full description of persist command in iRule

It is use full info but i have miss understanding.

I have VIP and on it have default persistence profile. also i have iRule on VIP that redirecting to different pools like:

  "/site1*" {
     persist cookie
      use pool pool1
          }  
  "/site2*" {
     persist none
     use pool pool2

  } 
 default {
     use pool defaultpool
  }

if i am not specify any persistence value that pool will get default persistence profile (like defaultpool), if i specify "persist none" pool will not get any persistence.

So the question what will be with pool1 that has "persist cookie"????

thanks