An nc program word is an acceptable letter followed by a real_value. Table 2 shows the current list of words that the EMC interpreter recognizes. The meanings of many of these words are listed in detail below. Some are included in and in the chapter on tool radius compensation and the chapter on canned cycles.
| A | A axis of machine |
| B | B axis of machine |
| C | C axis of machine |
| D | Tool radius compensation number |
| F | Feed rate |
| G | General Function (see below) |
| H | Toool length offset |
| I | X-axis offset for arcs |
| X offset in G87 canned cycle | |
| J | Y-axis offset for arcs |
| and Y offset in G87 canned cycle | |
| K | Z-axis offset for arcs |
| and Z offset in G87 canned cycle | |
| L | L number of repetitions in canned cycles
and key used with G10 |
| M | Miscellaneous function (see below) |
| N | Line number |
| P | Dwell time with G4 and canned cycles
key used with G10 |
| Q | Feed increment in G83 canned cycle |
| R | Arc radius |
| S | Spindle speed |
| T | Tool selection |
| X | X axis of machine |
| Y | Y axis of machine |
| Z | Z axis of machine |
Table 2 Words acceptable to the EMC interpreter