How does Gameshark do this?

Max Total Point Codes (Separated/Condensed)

72 Squire 8005800A FFFF

73 Chemist 8005800C FFFF

74 Knight 8005800E FFFF

75 Archer 80058010 FFFF

76 Monk 80058012 FFFF

77 Priest 80058014 FFFF

78 Wizard 80058016 FFFF

79 Time Mage 80058018 FFFF

80 Summoner 8005801A FFFF

81 Thief 8005801C FFFF

82 Mediator 8005801E FFFF

83 Oracle 80058020 FFFF

84 Geomancer 80058022 FFFF

85 Lancer 80058024 FFFF

86 Samurai 80058026 FFFF

87 Ninja 80058028 FFFF

88 Calculator 8005802A FFFF

89 Bard 8005802C FFFF

90 Mime 8005802E FFFF

91 All Jobs (GS 2.2 Or Higher Needed!)

50001302 0000
8005800A FFFF

Notice the last code.., How does it accomplish everything that all the other codes do alone?

Now, codes work like this:

zz yyyyyy xxxx

z= rule byte (if 30 then xxxx is a 1 byte value, If 80 then a 2byte value) There are other rules also.

y= the address

x= the value