It's always hard to figure out what a Mustad hook is used for or anything about the hook. This might help:

 Signature Series

C49S CADDIS, CURVED

CURVED, FORGED, CHEMICALLY SHARPENED SIGNATURE POINT, NOR-TEMPERED, MICRO BARB, STANDARD WIRE, 1 EXTRA SHORT, STRAIGHT EYE, BRONZED SIZES: 6-28R30 DRY ROUND BEND, FORGED, CHEMICALLY SHARPENED SIGNATURE POINT, NOR-TEMPERED, MICRO BARB, 2 EXTRA FINE, STANDARD LENGTH, TURNED DOWN EYE, BRONZED

SIZES: 12-28R74 STREAMER

ROUND BEND, FORGED, CHEMICALLY SHARPENED SIGNATURE POINT, NOR-TEMPERED, MICRO BARB, 2 EXTRA STRONG, 4 EXTRA LONG, TURNED DOWN EYE, BRONZED

SIZES: 2 -10 

R48 CADDIS, SHORT

ROUND BEND, FORGED, CHEMICALLY SHARPENED SIGNATURE POINT, NOR-TEMPERED, MICRO BARB, STANDARD WIRE, 2 EXTRA SHORT, TURNED DOWN EYE, BRONZED

SIZES: 8-16

R50 DRY/ WETROUND BEND, FORGED, CHEMICALLY SHARPENED SIGNATURE POINT, NOR-TEMPERED, MICRO BARB, STANDARD WIRE, STANDARD LENGTH, TURNED DOWN EYE, BRONZEDSIZES: 2-28

C52S BLN STINGER, DEER HAIR OPEN BEND, FORGED, CHEMICALLY SHARPENED SIGNATURE POINT, NOR-TEMPERED, MICRO BARB, 2 EXTRA STRONG, 3 EXTRA LONG, STRAIGHT EYE, BRONZED

SIZES: 2-10 

C67S EGG, CADDISCURVED, FORGED, CHEMICALLY SHARPENED SIGNATURE POINT, NOR-TEMPERED, MICRO BARB, 2 EXTRA STRONG, 3 EXTRA SHORT, STRAIGHT EYE, BRONZEDSIZES: 4-14

R70 NYMPH, HEAVY ROUND BEND, FORGED, CHEMICALLY SHARPENED SIGNATURE POINT, NOR-TEMPERED, MICRO BARB, 2 EXTRA STRONG, STANDARD LENGTH, TURNED DOWN EYE, BRONZED

SIZES: 6-16R72 NYMPH, LONG

ROUND BEND, FORGED, CHEMICALLY SHARPENED SIGNATURE POINT, NOR-TEMPERED, MICRO BARB, 2 EXTRA STRONG, 2 EXTRA LONG, TURNED DOWN EYE, BRONZED

SIZES: 6-16 C53S NYMPH, LONG, CURVED

CURVED, FORGED, CHEMICALLY SHARPENED SIGNATURE POINT, NOR-TEMPERED, MICRO BARB, STANDARD WIRE, 3 EXTRA LONG, STRAIGHT EYE, BRONZED

SIZES: 6-16

R90 NYMPH, SUPER HEAVYROUND BEND, FORGED, CHEMICALLY SHARPENED SIGNATURE POINT, NOR-TEMPERED, MICRO BARB, 4 EXTRA STRONG, STANDARD LENGTH, TURNED DOWN EYE, BRONZEDSIZES: 4, 6, 8

CK52S POPPER KINK SHANK SPROAT, FORGED, CHEMICALLY SHARPENED SIGNATURE POINT, NOR-TEMPERED, MICRO BARB, STANDARD WIRE, 2 EXTRA LONG, STRAIGHT EYE, BRONZED

SIZES: 2/0-14

 Classic Series

94840 – Wet and Dry Fly VIKING, FORGED, EXTRA FINE WIRE, STRAIGHT, ROUND BEND, TURNED DOWN TAPERED EYE, BRONZED

SIZES: 2-2694833 – Dry Fly

VIKING, FORGED, 3 EXTRA FINE WIRE, STRAIGHT, ROUND BEND, TURNED DOWN TAPERED EYE, BRONZED

SIZES: 6-2294842 – Dry Fly

VIKING, FORGED, EXTRA FINE WIRE, STRAIGHT, ROUND BEND, TURNED UP TAPERED EYE, BRONZED

SIZES: 4-26 

94845 – Dry Fly

VIKING, FORGED, EXTRA FINE WIRE, STRAIGHT, ROUND BEND, TURNED DOWN TAPERED EYE, BARBLESS, BRONZED

SIZES: 8-18

539E – Dry Fly3x FINE, FORGED, REVERSED POINT, SHORT SHANK, TAPERED EYE, BRONZEDSIZES: 2-18

540 – Wet Fly FORGED, REVERSED POINT, RING EYE, BRONZED

SIZES: 2-16 

80250BR – Shrimp & Caddis Pupae Forged Bend, Round Eye, Microbarb, Reversed PointSIZES: 10-16

540L – Wet Fly

FORGED, REVERSED POINT, RING EYE, GOLD

SIZES: 10-163906B – Wet Fly

SPROAT, EX STRONG, TURNED DOWN TAPERED EYE, BRONZED

SIZES: 4-16 80000BR – Extra Light Dry FORGED, KNIFE EDGE POINT, CHEMICALLY SHARPENED, NOR-TEMPERED, MICRO BARB, TURNED DOWN 30 DEGREE BALL EYE, BRONZED SIZES: 10-20

79580 – Streamer VIKING, 4 EXTRA LONG SHANK, FORGED, STRAIGHT, TURNED DOWN TAPERED EYE, BRONZEDSIZES: 2-12

36890 – Salmon Single – Wet