Definition

Many systems share familiar motion such as G0/G1, but that overlap is not one universal printer language. Marlin features can depend on compile-time options, Klipper deliberately combines a common command subset with named extended commands and configurable macros, RepRapFirmware uses G-code extensively for configuration, and CNC controllers add their own modal groups and meanings.

Selecting a flavor in a slicer changes what the slicer writes. It is evidence of the intended target, not proof of the firmware actually installed in a printer. Vendor forks, machine profiles, post-processing, and custom macros can all change the file or its behavior. A file header that names Marlin therefore supports the limited statement 'the file targets a Marlin-compatible flavor,' not 'this machine definitely runs upstream Marlin.'

What matters in practice

An output contract

The flavor guides which command forms and defaults a slicer emits for the intended controller.

Shared code, different meaning

A familiar number such as G28 can mean printer homing in one context and a stored-reference return in a CNC context.

Extensions are part of the dialect

Klipper named commands, RepRapFirmware expressions, vendor commands, and user macros may be valid only in their configured environment.

Not a firmware fingerprint

Profile names and file comments cannot prove the printer's real firmware, version, enabled features, or macro definitions.

Example in G-code

One concept, three non-interchangeable commands

; Same concept, different dialect-specific commands
M900 K0.18 ; Marlin Linear Advance
SET_PRESSURE_ADVANCE ADVANCE=0.04 ; Klipper
M572 D0 S0.10 ; RepRapFirmware

The lines show firmware-specific ways to configure pressure compensation. Their names and numeric values cannot be copied between dialects as equivalent syntax.

What this viewer can show

In this viewer

The viewer recognizes a tested subset of commands and can identify some slicer signatures from explicit comments. It does not certify the printer firmware from a flavor label. Unknown macros or controller-specific behavior may remain unmodeled, so inspect the source and the target firmware documentation before sending a file to a machine.

Primary sources

This explanation uses firmware documentation and details visible in G-code. Your printer's settings still determine what the machine does.