Configuration files for my Duet-based 3D Printers
I use VSCode generally when modifying gcode files, and the GCode extension is very helpful in that manner.
It supports hover-over gcode definitions. Below you will find a definition set from the Duet GCode Wiki you can place in your settings.json to populate your definition list with the extension.
"gcode.definitions": {
"G0": "Move, rapid, linear interpolation",
"G1": "Move, feed, linear interpolation",
"G2": "Move, feed, circular interpolation, clockwise",
"G3": "Move, feed, circular interpolation, counterclockwise",
"G4": "Dwell",
"G10": "Retract, L/P/R/S: Offset/Tool/Temp Setting",
"G11": "Unretract",
"G17": "Select XY plane for arc moves",
"G20": "Set Units to Inches",
"G21": "Set Units to Millimeters",
"G28": "Home",
"G29": "Mesh bed probe",
"G30": "Single Z-Probe",
"G31": "Set or Report Current Probe status",
"G32": "Run bed.g macro",
"G38.2": "Probe toward workpiece, stop on contact, signal error if failue",
"G38.3": "Probe toward workpiece, stop on contact",
"G38.4": "Probe away from workpiece, stop on loss of contact, signal error if failure",
"G38.5": "Probe away from workpiece, stop on loss of contact",
"G53": "Use machine coordinates",
"G54": "Select coordinate system 1",
"G55": "Select coordinate system 2",
"G56": "Select coordinate system 3",
"G57": "Select coordinate system 4",
"G58": "Select coordinate system 5",
"G59": "Select coordinate system 6",
"G59.1": "Select coordinate system 7",
"G59.2": "Select coordinate system 8",
"G59.3": "Select coordinate system 9",
"G60": "Save current position to slot",
"G90": "Set to Absolute Positioning",
"G91": "Set to Relative Positioning",
"G92": "Set Position",
"M0": "Stop or Unconditional stop",
"M1": "Sleep or Conditional stop",
"M3": "Spindle On, Clockwise (CNC specific)/ Laser on (Laser specific)",
"M4": "Spindle On, Counterclockwise (CNC specific)",
"M5": "Spindle Off (CNC specific), laser off (Laser specific)",
"M18": "Disable all stepper motors",
"M20": "List SD card",
"M21": "Initialize SD card",
"M22": "Release SD card",
"M23": "Select SD file",
"M24": "Start/resume SD print",
"M25": "Pause SD print",
"M26": "Set SD position",
"M27": "Report SD print status",
"M28": "Begin write to SD card",
"M29": "Stop writing to SD card",
"M30": "Delete a file on the SD card",
"M32": "Select file and start SD print",
"M36": "Return file information",
"M37": "Simulation mode",
"M38": "Compute SHA1 hash of target file",
"M39": "Report SD card information",
"M42": "Switch I/O pin",
"M80": "ATX Power On",
"M81": "ATX Power Off",
"M82": "Set extruder to absolute mode",
"M83": "Set extruder to relative mode",
"M84": "Stop idle hold",
"M92": "Set axis steps per unit",
"M98": "Call Macro/Subprogram",
"M99": "Return from Macro/Subprogram",
"M104": "Set Extruder Temperature",
"M105": "Get Extruder Temperature",
"M106": "Fan On",
"M107": "Fan Off",
"M108": "Cancel Heating",
"M109": "Set Extruder Temperature and Wait",
"M110": "Set Current Line Number",
"M111": "Set Debug Level",
"M112": "Emergency Stop",
"M114": "Get Current Position",
"M115": "Get Firmware Version and Capabilities",
"M116": "Wait",
"M117": "Display Message",
"M118": "Send Message to Specific Target",
"M119": "Get Endstop Status",
"M120": "Push",
"M121": "Pop",
"M122": "Diagnose",
"M135": "Set PID sample interval",
"M140": "Set Bed Temperature (Fast) or Configure Bed Heater",
"M141": "Set Chamber Temperature (Fast) or Configure Chamber Heater",
"M143": "Maximum heater temperature",
"M144": "Bed Standby",
"M150": "Set LED colours",
"M190": "Wait for bed temperature to reach target temp",
"M191": "Wait for chamber temperature to reach target temp",
"M200": "Set filament diameter",
"M201": "Set max acceleration",
"M203": "Set maximum feedrate",
"M204": "Set printing and travel accelerations",
"M205": "Set max instantaneous speed change in mm/sec",
"M206": "Offset axes",
"M207": "Set retract length",
"M208": "Set axis max travel",
"M220": "Set speed factor override percentage",
"M221": "Set extrude factor override percentage",
"M226": "Synchronous Pause",
"M260": "i2c Send and/or request Data",
"M261": "i2c Request Data",
"M280": "Set servo position",
"M290": "Baby stepping",
"M291": "Display message and optionally wait for response",
"M292": "Acknowledge message",
"M300": "Play beep sound",
"M301": "Set PID parameters",
"M302": "Allow cold extrudes",
"M303": "Run heater tuning",
"M304": "Set PID parameters - Bed",
"M305": "Set temperature sensor parameters",
"M307": "Set or report heating process parameters",
"M308": "Set or report sensor parameters",
"M350": "Set microstepping mode",
"M374": "Save height map",
"M375": "Load height map",
"M376": "Set bed compensation taper",
"M400": "Wait for current moves to finish",
"M401": "Deploy z-probe",
"M402": "Retract z-probe",
"M404": "Filament width and nozzle diameter",
"M408": "Report JSON-style response",
"M409": "Query object model",
"M450": "Report Printer Mode",
"M451": "Select FFF Printer Mode",
"M452": "Select Laser DeviceMode",
"M453": "Select CNC Device Mode",
"M470": "Create Directory on SD-Card",
"M471": "Rename File/Directory on SD-Card",
"M486": "Object cancellation",
"M500": "Store parameters",
"M501": "Read stored parameters",
"M502": "Revert stored parameters",
"M503": "Print settings",
"M505": "Set configuration file folder",
"M540": "Set MAC address",
"M550": "Set Name",
"M551": "Set Password",
"M552": "Set IP address, enable/disable network interface",
"M553": "Set Netmask",
"M554": "Set Gateway",
"M555": "Set compatibility",
"M556": "Axis skew compensation",
"M557": "Set Z probe point or define probing grid",
"M558": "Set Z probe type",
"M559": "Upload file",
"M560": "Upload file",
"M561": "Set Identity Transform",
"M562": "Reset temperature fault",
"M563": "Define or remove a tool",
"M564": "Limit axes",
"M566": "Set allowable instantaneous speed change",
"M567": "Set tool mix ratios",
"M568": "Turn off/on tool mix ratios",
"M569": "Set motor driver direction, enable polarity and step pulse timing",
"M569.1": "Stepper driver closed loop control",
"M570": "Configure heater fault detection",
"M571": "Set output on extrude",
"M572": "Set or report extruder pressure advance",
"M573": "Report heater PWM",
"M574": "Set endstop configuration",
"M575": "Set serial comms parameters",
"M577": "Wait until endstop is triggered",
"M578": "Fire inkjet bits",
"M579": "Scale Cartesian axes",
"M580": "Select Roland",
"M581": "Configure external trigger",
"M582": "Check external trigger",
"M584": "Set drive mapping",
"M585": "Probe Tool",
"M586": "Configure network protocols",
"M587": "Add WiFi host network to remembered list, or list remembered networks",
"M588": "Forget WiFi host network",
"M589": "Configure access point parameters",
"M591": "Configure filament sensing",
"M592": "Configure nonlinear extrusion",
"M593": "Configure Dynamic Acceleration Adjustment",
"M594": "Enter/Leave Height Following mode",
"M595": "Set movement queue length",
"M600": "Filament change pause",
"M650": "Set peel move parameters",
"M651": "Execute peel move",
"M665": "Set delta configuration",
"M666": "Set delta endstop adjustment",
"M667": "Select CoreXY or related mode",
"M669": "Set kinematics type and kinematics parameters",
"M670": "Set IO port bit mapping",
"M671": "Define positions of Z leadscrews or bed levelling screws",
"M672": "Program Z probe",
"M673": "Align plane on rotary axis",
"M674": "Set Z to center point",
"M675": "Find center of cavity",
"M701": "Load filament",
"M702": "Unload filament",
"M703": "Configure filament",
"M750": "Enable 3D scanner extension",
"M751": "Register 3D scanner extension over USB",
"M752": "Start 3D scan",
"M753": "Cancel current 3D scanner action",
"M754": "Calibrate 3D scanner",
"M755": "Set alignment mode for 3D scanner",
"M756": "Shutdown 3D scanner",
"M851": "Set Z-Probe Offset (Marlin Compatibility)",
"M905": "Set local date and time",
"M906": "Set motor currents",
"M911": "Configure auto save on loss of power",
"M912": "Set electronics temperature monitor adjustment",
"M913": "Set motor percentage of normal current",
"M914": "Set/Get Expansion Voltage Level Translator",
"M915": "Configure motor stall detection",
"M916": "Resume print after power failure",
"M917": "Set motor standstill current reduction",
"M918": "Configure direct-connect display",
"M929": "Start/stop event logging to SD card",
"M950": "Create heater, fan or GPIO/servo pin",
"M951": "Set height following mode parameters",
"M952": "Set CAN-FD expansion board address and/or normal data rate",
"M953": "Set CAN-FD bus fast data rate",
"M954": "Configure as CAN expansion board",
"M998": "Request resend of line",
"M999": "Restart",
"T": "Report selected tool",
"T-1": "Deselect all tools",
"T0": "Select Tool 0",
"T1": "Select Tool 1",
"T2": "Select Tool 2",
"T3": "Select Tool 3",
"T4": "Select Tool 4",
"T5": "Select Tool 5",
"T6": "Select Tool 6",
"T7": "Select Tool 7",
"T8": "Select Tool 8"
}