51: En route
42: Home/house
97: arrive
48: msg rec'd
25: contact via
88: phone
23: standby
22: disregard

The above codes I learned from an actual officer. The following codes I got from the internet. I'm sure there are more, but this is going to have to suffice.

They all start w/ 10, so I'm just going to add the 2nd #.

0: caution
1: signal weak
2: signal good
3: stop transmitting
4: msg rec'd
5: relay
6: busy
7: out of service
8: in service
9: repeat
10: fight in progress
11: animal problem
12: stand by
13: report conditions
14: prowler report
15: civil disturbance
16: domestic problem
17: meet compianant
18: urgent
19: go to station
20: location
21: phone ___
22: disregard
23: arrived at scene
24: assignment complete
25: report to ___
26: detaining suspect
27: drivers license info
28: vehicle registration info
29: check for wants/warrants
30: unauthorized use of radio
31: crime in progress
32: person w/ gun
33: emergency, stand by
34: riot
35: major crime alert
36 correct time
37: investigate suspicious vehicle
38: stop suspiciuos vehicle
39: use lights and sirens
40: respond quickly
41: beginning shift
42: ending shift
43: info
44: permission to leave
45: dead animal
46: assist motorist
47: emergency road repair
48: traffic control
49: traffic signal out
50: traffic accident
51: request tow truck
52: request ambulance
53: roadway blocked
54: livestock on roadway
55: intoxicated driver
56: intoxicated pedestrian
57: hit and run accident
58: direct traffic
59: escort
60: squad in vicinity
61: personnel in vicinity
62: reply to msg
63: prepare to copy
64: local msg
65: network msg
66: cancel msg
67: clr for network msg
68: dispatch info
69: msg rec'd
70: fire alarm
71: advise of nature of fire
72: report progress of fire
73: smoke report
74: negative
75: in contact w/ ___
76: en route to ____
77: eta
78: request assistance
79: notify coroner
80: pursuit in progress
81: breathalyer report
82: reserve lodgings
83: school crossing detail
84: eta
85: arrival delayed
86: operator on duty
87: pick up
88: advise of telephone #
89: bomb threat
90: bank alarm
91: pick up subject
92: illegally parked vehicle
93: blockage
94: drag racing
95: subject in custody
96: detain subject
97: test signal
98: escaped prisoner
99: wanted or stolen

Not sure but seems that this doesn't fall in line w/ what I've been told so far...maybe from another city...maybe jurisdictions have their own unique set of codes?