I really think that code words have gotten silly.
Most robbers have worked retail before at some point in their life. Every retailer uses code words. If anyone is serious about pulling off a robbery, they are going to find out the code words. (or know them already)
The one exception to this are internal AP code words. I will never forget about 3 years ago when I was a TL, the ETLs were so damn idiotic that they sent out quite a few walkies and asked for them to be programmed to go up to channel 4. (we were a 2 channel store)
Of course, the extra two channels are for AP. Problem is, the ETLs didn't do a good job making sure that only ETLs got the those walkies. Eventually myself and others got our hands on them. (totally by accident.... just randomly got them from the equipment cabinet) Man.... talk about some interesting stuff that AP talks about. Even on their own channels, they use code words. Had no idea what they were talking about sometimes due to those code words, but they were highly effective.
Turns out that this was actually a violation of policy when higher ups found out what the ETLs had done a few months later. Apparently no one other than AP is *ever* supposed to have a walkie that has the AP channels, and that includes non-AP ETLs. So all the 4 channel walkies were taken away.