fstab swap options obscolete?

[safemode]

In order to get multiple swap partitions/files to work at the same priority, 
you'd use the pri=NUM option in /etc/fstab.   
Now i've set this (pri=-1) on both and dmesg shows that they still get added 
at different priorities.  first -1, second -2.   Now if i swapoff them and 
swapon them  it starts at -3   even though there is no longer a -1 or -2.  Is 
this correct behavior?     
I'm kinda going on the assumption that loading multiple swap partitions 
together at the same priority will basically make the kernel use them in a 
striping mode.  Is this the case?   If not, how would i specifiy priority 
besides merely the order they're placed in /etc/fstab  ?