Client 1.23.0:
Packet 00 : 98 bytes (0x62)
Packet 01 : 5 bytes (0x5)
Packet 02 : 3 bytes (0x3)
Packet 03 : dynamic (0x8000)
Packet 04 : 2 bytes (0x2)
Packet 05 : 5 bytes (0x5)
Packet 06 : 5 bytes (0x5)
Packet 07 : 7 bytes (0x7)
Packet 08 : 14 bytes (0xE)
Packet 09 : 5 bytes (0x5)
Packet 0A : 11 bytes (0xB)
Packet 0B : 266 bytes (0x10A)
Packet 0C : dynamic (0x8000)
Packet 0D : 3 bytes (0x3)
Packet 0E : dynamic (0x8000)
Packet 0F : 61 bytes (0x3D)
Packet 10 : 215 bytes (0xD7)
Packet 11 : dynamic (0x8000)
Packet 12 : dynamic (0x8000)
Packet 13 : 10 bytes (0xA)
Packet 14 : 6 bytes (0x6)
Packet 15 : 9 bytes (0x9)
Packet 16 : 1 bytes (0x1)
Packet 17 : dynamic (0x8000)
Packet 18 : dynamic (0x8000)
Packet 19 : dynamic (0x8000)
Packet 1A : 19 bytes (0x13)
Packet 1B : 37 bytes (0x25)
Packet 1C : dynamic (0x8000)
Packet 1D : 5 bytes (0x5)
Packet 1E : 4 bytes (0x4)
Packet 1F : 8 bytes (0x8)
Packet 20 : 19 bytes (0x13)
Packet 21 : 8 bytes (0x8)
Packet 22 : 2 bytes (0x2)
Packet 23 : 26 bytes (0x1A)
Packet 24 : 7 bytes (0x7)
Packet 25 : 20 bytes (0x14)
Packet 26 : 5 bytes (0x5)
Packet 27 : 2 bytes (0x2)
Packet 28 : 5 bytes (0x5)
Packet 29 : 1 bytes (0x1)
Packet 2A : 5 bytes (0x5)
Packet 2B : 2 bytes (0x2)
Packet 2C : 2 bytes (0x2)
Packet 2D : 17 bytes (0x11)
Packet 2E : 15 bytes (0xF)
Packet 2F : 10 bytes (0xA)
Packet 30 : 5 bytes (0x5)
Packet 31 : 1 bytes (0x1)
Packet 32 : 2 bytes (0x2)
Packet 33 : 2 bytes (0x2)
Packet 34 : 10 bytes (0xA)
Packet 35 : 653 bytes (0x28D)
Packet 36 : dynamic (0x8000)
Packet 37 : 8 bytes (0x8)
Packet 38 : 7 bytes (0x7)
Packet 39 : 9 bytes (0x9)
Packet 3A : dynamic (0x8000)
Packet 3B : dynamic (0x8000)
Packet 3C : dynamic (0x8000)
Packet 3D : 2 bytes (0x2)
Packet 3E : 37 bytes (0x25)
Packet 3F : dynamic (0x8000)
Packet 40 : 201 bytes (0xC9)
Packet 41 : dynamic (0x8000)
Packet 42 : dynamic (0x8000)
Packet 43 : 553 bytes (0x229)
Packet 44 : 713 bytes (0x2C9)
Packet 45 : 5 bytes (0x5)
Packet 46 : dynamic (0x8000)
Packet 47 : 11 bytes (0xB)
Packet 48 : 73 bytes (0x49)
Packet 49 : 93 bytes (0x5D)
Packet 4A : 5 bytes (0x5)
Packet 4B : 9 bytes (0x9)
Packet 4C : dynamic (0x8000)
Packet 4D : dynamic (0x8000)
Packet 4E : 6 bytes (0x6)
Packet 4F : 2 bytes (0x2)
Packet 50 : dynamic (0x8000)
Packet 51 : dynamic (0x8000)
Packet 52 : dynamic (0x8000)
Packet 53 : 2 bytes (0x2)
Packet 54 : 12 bytes (0xC)
Packet 55 : 1 bytes (0x1)
Packet 56 : 11 bytes (0xB)
Packet 57 : 110 bytes (0x6E)
Packet 58 : 106 bytes (0x6A)
Packet 59 : dynamic (0x8000)
Packet 5A : dynamic (0x8000)
Packet 5B : 4 bytes (0x4)
Packet 5C : 2 bytes (0x2)
Packet 5D : 73 bytes (0x49)
Packet 5E : dynamic (0x8000)
Packet 5F : 49 bytes (0x31)
Packet 60 : 5 bytes (0x5)
Packet 61 : 9 bytes (0x9)
Packet 62 : 15 bytes (0xF)
Packet 63 : 13 bytes (0xD)
Packet 64 : 1 bytes (0x1)
Packet 65 : 4 bytes (0x4)
Packet 66 : dynamic (0x8000)
Packet 67 : 21 bytes (0x15)
Packet 68 : dynamic (0x8000)
Packet 69 : dynamic (0x8000)
Packet 6A : 3 bytes (0x3)
Packet 6B : 9 bytes (0x9)
Packet 6C : 18 bytes (0x12)
Packet 6D : 3 bytes (0x3)
Packet 6E : 14 bytes (0xE)
Packet 6F : dynamic (0x8000)
Packet 70 : 28 bytes (0x1C)
Packet 71 : dynamic (0x8000)
Packet 72 : 5 bytes (0x5)
Packet 73 : 2 bytes (0x2)
Packet 74 : dynamic (0x8000)
Packet 75 : 35 bytes (0x23)
Packet 76 : 16 bytes (0x10)
Packet 77 : 16 bytes (0x10)
Packet 78 : dynamic (0x8000)
Packet 79 : 9 bytes (0x9)
Packet 7A : dynamic (0x8000)
Packet 7B : 2 bytes (0x2)
Packet 7C : dynamic (0x8000)
Packet 7D : 13 bytes (0xD)
Packet 7E : 2 bytes (0x2)
Packet 7F : dynamic (0x8000)
Packet 80 : 62 bytes (0x3E)
Packet 81 : dynamic (0x8000)
Packet 82 : 2 bytes (0x2)
Packet 83 : 39 bytes (0x27)
Packet 84 : 69 bytes (0x45)
Packet 85 : 2 bytes (0x2)
Packet 86 : dynamic (0x8000)
Packet 87 : dynamic (0x8000)
Packet 88 : 66 bytes (0x42)
Packet 89 : 109 bytes (0x6D)
Packet 8A : dynamic (0x8000)
Packet 8B : dynamic (0x8000)
Packet 8C : 11 bytes (0xB)
Packet 8D : dynamic (0x8000)
Packet 8E : dynamic (0x8000)
Packet 8F : dynamic (0x8000)
Packet 90 : 19 bytes (0x13)
Packet 91 : 2 bytes (0x2)
Packet 92 : dynamic (0x8000)
Packet 93 : 98 bytes (0x62)
Packet 94 : dynamic (0x8000)
Packet 95 : 9 bytes (0x9)
Packet 96 : dynamic (0x8000)
Packet 97 : 2 bytes (0x2)
Packet 98 : dynamic (0x8000)
Packet 99 : 26 bytes (0x1A)
Packet 9A : dynamic (0x8000)
Packet 9B : 2 bytes (0x2)
Packet 9C : 53 bytes (0x35)
Packet 9D : 51 bytes (0x33)
Client 1.23.37b:
+Packet 00 : 100 bytes (0x64)
-Packet 00 : 98 bytes (0x62)
-Packet 1A : 19 bytes (0x13)
+Packet 1A : dynamic (0x8000)
-Packet 89 : 109 bytes (0x6D)
+Packet 89 : dynamic (0x8000)
-Packet 91 : 2 bytes (0x2)
+Packet 91 : 65 bytes (0x41)
-Packet 9B : 2 bytes (0x2)
+Packet 9B : 258 bytes (0x102)
+Packet 9C : 309 bytes (0x135)
-Packet 9C : 53 bytes (0x35)
+Packet 9E : dynamic (0x8000)
+Packet 9F : dynamic (0x8000)
+Packet A0 : 3 bytes (0x3)
+Packet A1 : 9 bytes (0x9)
+Packet A2 : 9 bytes (0x9)
+Packet A3 : 9 bytes (0x9)
+Packet A4 : 149 bytes (0x95)
Client 1.25.35:
-Packet 22 : 2 bytes (0x2)
+Packet 22 : 3 bytes (0x3)
-Packet 6C : 18 bytes (0x12)
+Packet 6C : 19 bytes (0x13)
-Packet 77 : 16 bytes (0x10)
+Packet 77 : 17 bytes (0x11)
+Packet A5 : dynamic (0x8000)
+Packet A6 : dynamic (0x8000)
+Packet A7 : 4 bytes (0x4)
+Packet A8 : dynamic (0x8000)
+Packet A9 : dynamic (0x8000)
+Packet AA : 5 bytes (0x5)
+Packet AB : dynamic (0x8000)
+Packet AC : dynamic (0x8000)
+Packet AD : dynamic (0x8000)
+Packet AE : dynamic (0x8000)
+Packet AF : 13 bytes (0xD)
+Packet B0 : dynamic (0x8000)
+Packet B1 : dynamic (0x8000)
+Packet B2 : dynamic (0x8000)
+Packet B3 : dynamic (0x8000)
+Packet B4 : dynamic (0x8000)
+Packet B5 : 64 bytes (0x40)
+Packet B6 : 9 bytes (0x9)
+Packet B7 : dynamic (0x8000)
+Packet B8 : dynamic (0x8000)
+Packet B9 : 3 bytes (0x3)
Client 1.26.0:
-Packet 00 : 100 bytes (0x64)
+Packet 00 : 104 bytes (0x68)
-Packet 02 : 3 bytes (0x3)
+Packet 02 : 7 bytes (0x7)
-Packet 93 : 98 bytes (0x62)
+Packet 93 : 99 bytes (0x63)
+Packet BA : 6 bytes (0x6)
+Packet BB : 9 bytes (0x9)
+Packet BC : 2 bytes (0x2)
+Packet BD : dynamic (0x8000)
+Packet BE : dynamic (0x8000)
+Packet BF : dynamic (0x8000)
Client 1.26.2:
+Packet C0 : 36 bytes (0x24)
+Packet C1 : dynamic (0x8000)
Client 1.26.3:
+Packet C2 : dynamic (0x8000)
Client 1.26.4b:
+Packet C3 : dynamic (0x8000)
Client 1.26.4i:
-Packet BC : 2 bytes (0x2)
+Packet BC : 3 bytes (0x3)
+Packet C4 : 6 bytes (0x6)
Client 2.0.0g:
+Packet C5 : 203 bytes (0xCB)
+Packet C6 : 1 bytes (0x1)
Client 2.0.3b:
+Packet C7 : dynamic (0x8000)
Client 2.0.4c:
+Packet C7 : 49 bytes (0x31)
-Packet C7 : dynamic (0x8000)
+Packet C8 : 2 bytes (0x2)
+Packet C9 : 6 bytes (0x6)
+Packet CA : 6 bytes (0x6)
+Packet CB : 7 bytes (0x7)
+Packet CC : dynamic (0x8000)
Client 3.0.3a:
+Packet CD : 1 bytes (0x1)
+Packet CE : dynamic (0x8000)
+Packet CF : dynamic (0x8000)
+Packet D0 : dynamic (0x8000)
+Packet D1 : dynamic (0x8000)
+Packet D2 : 25 bytes (0x19)
+Packet D3 : dynamic (0x8000)
+Packet D4 : dynamic (0x8000)
Client 3.0.4m:
+Packet CF : 78 bytes (0x4E)
-Packet CF : dynamic (0x8000)
+Packet D1 : 2 bytes (0x2)
-Packet D1 : dynamic (0x8000)
Client 3.0.8z0:
+Packet D5 : dynamic (0x8000)
+Packet D6 : dynamic (0x8000)
+Packet D7 : dynamic (0x8000)
+Packet D8 : dynamic (0x8000)
Client 4.0.00o:
+Packet D9 : 202 bytes (0xCA)
Client 4.0.00q:
+Packet DA : dynamic (0x8000)
Client 4.0.01a:
-Packet D9 : 202 bytes (0xCA)
+Packet D9 : 268 bytes (0x10C)
Client 4.0.02a:
+Packet DB : dynamic (0x8000)
Client 4.0.04t:
+Packet DC : 9 bytes (0x9)
Client 4.0.07a:
-Packet 0B : 266 bytes (0x10A)
+Packet 0B : 7 bytes (0x7)
Client 4.0.10a:
-Packet 16 : 1 bytes (0x1)
+Packet 16 : dynamic (0x8000)
-Packet 31 : 1 bytes (0x1)
+Packet 31 : dynamic (0x8000)
Client 5.0.0a:
+Packet DD : dynamic (0x8000)
Client 5.0.2:
+Packet DE : dynamic (0x8000)
+Packet DF : dynamic (0x8000)
Client 5.0.9.0:
+Packet E0 : dynamic (0x8000)
+Packet E1 : dynamic (0x8000)
+Packet E2 : 10 bytes (0xA)
Client 6.0.01.03:
+Packet E3 : dynamic (0x8000)
+Packet E4 : dynamic (0x8000)
+Packet E5 : dynamic (0x8000)
+Packet E6 : 5 bytes (0x5)
+Packet E7 : 12 bytes (0xC)
+Packet E8 : 13 bytes (0xD)
+Packet E9 : 75 bytes (0x4B)
+Packet EA : 3 bytes (0x3)
+Packet EB : dynamic (0x8000)
+Packet EC : dynamic (0x8000)
+Packet ED : dynamic (0x8000)
Client 6.0.01.07:
-Packet 08 : 14 bytes (0xE)
+Packet 08 : 15 bytes (0xF)
-Packet 25 : 20 bytes (0x14)
+Packet 25 : 21 bytes (0x15)
Client 6.0.06.0:
+Packet EE : 8192 bytes (0x2000)
+Packet EF : 8192 bytes (0x2000)
+Packet F0 : dynamic (0x8000)
+Packet F1 : 9 bytes (0x9)
+Packet F2 : 25 bytes (0x19)
Client 6.0.06.1:
-Packet EE : 8192 bytes (0x2000)
-Packet EF : 8192 bytes (0x2000)
-Packet F0 : dynamic (0x8000)
-Packet F1 : 9 bytes (0x9)
-Packet F2 : 25 bytes (0x19)
Client 6.0.14.2:
-Packet B9 : 3 bytes (0x3)
+Packet B9 : 5 bytes (0x5)
Client 7.0.0.0:
+Packet EE : 8192 bytes (0x2000)
+Packet EF : 8192 bytes (0x2000)
+Packet F0 : 8192 bytes (0x2000)
+Packet F1 : 8192 bytes (0x2000)
+Packet F2 : 8192 bytes (0x2000)
+Packet F3 : 24 bytes (0x18)
Over on the JoinUO (freeshard listing service) forums, "Batlin" posted a list of nearly all packet-size changes done in the 2D client since v1.23.0 (with some early versions missing). Seems like a useful reference, so I'll repost it here: