SAMOA

All banknotes of the 1985-90 issue (P-25, 26, 27, 28, 29, 30)
have a solid foil over the security thread,

while the banknotes of the 2002 issue (P-33, 34, 35, New[29], New[30])
 have a segmented foil over the security thread.    

1985-90 issue                                   2002 issue    
↓ ↓                ↓ ↓

___________________________

Also, 5, 10 and 20 Tala of the 1985 issue have one signature
(Minister of Finance).

while 5, 10 and 20 Tala of the 2002 issue have two signatures
(Minister of Finance and Governor)

1985 issue                                                                2002 issue    
↓ ↓                     ↓ ↓

50 and 100 Tala (both 1990 and 2002 issues) have two signatures.

_________________________________________________________

IN SHORT:

  5 Tala  P-26:  solid foil over security thread, 1 signature               
5 Tala  P-33:  segmented foil over security thread, 2 signatures

10 Tala  P-27:  solid foil over security thread, 1 signature             
10 Tala  P-34:  segmented foil over security thread, 2 signatures

20 Tala  P-28:  solid foil over security thread, 1 signature             
20 Tala  P-35:  segmented foil over security thread, 2 signatures

50 Tala  P-29:  solid foil over security thread, 2 signatures                      
50 Tala  P-New[29]:  segmented foil over security thread, 2 signatures

100 Tala  P-30:  solid foil over security thread, 2 signatures                      
100 Tala  P-New[30]:  segmented foil over security thread, 2 signatures