NO, it means Normal, as opposed to inverted which would be "i"
"code" and "tone" are the same thing, but you are probably looking in the CTCSS section.. Check the DTC/DCS section of the chart to find 053
It's on the chart (probably) but if not, you do not need it.. the RECEIVE tone is 100% optional, so forget about it for now. The TX (Transmit) tone is the only one you really need to care about
These are very nice, easy to use GMRS radios, although they are limited in what they can do (like most Midland radios), but having actually used them, I can confirm that they are good radios that perform 100% as well as any other GMRS radio. And, just like all GMRS radios they are 100% compatible with all other GMRS radios, FRS radios, and even the Motorola XTL5000 radios in both of my Jeeps and my handheld Motorola XTS5000 radios. Anyone here claiming otherwise has 1) never used or tested one, and 2) is just trying to get attention to make up for the attention that their mother never gave them... Those people should be ignored.