What does police code 5 mean?

Code 5 indicates "stakeout," 10-5 indicates "replay message"

Another View: Police 10-codes and radio 'lingo' is not uniform across the entire nation. Many agencies modify these codes so that they are unique to their own area or mode of operation. What a specific radio code means in one area or organization may not (and usually doesn't) mean the same in another location.