As a lineage from the Classic MacOS operating system, Apple still uses 4CC or 4 character codes pervasively. This helps you identify an unknown 4 ASCII sequence
| 4CC | Usage | Description |
|---|---|---|
| 0Cfg | SysCfg | |
| AAPL | Everwhere | Generic 4CC for Apple, often Creator Code |
| ADDA | SysCfg | |
| anef | Firmware | Apple Neural Engine Firmware |
| ansf | Firmware | Apple NAND Storage Firmware |
| aopf | Firmware | Always-on-Processor Firmware |
| appv | FDR, SysCfg | |
| aubt | ||
| auxi | Boot Policy | Auxiliary Kernel Cache Image4 Hash |
| auxp | Boot Policy | User Authorized Kext List Hash |
| auxr | Boot Policy | Kext Receipt Hash |
| avef | Firmware | Audio / Video Encryption (DRM) Firmware |
| BORD | ||
| BNDL | macOS | Loadable Bundle (plugin) |
| bstc | ||
| CEPO | APTicket | Certificate Epoch |
| CHIP | APTicket | Chip ID |
| coih | ||
| CPRO | Boot Policy | Chip Production Status |
| CSEC | ||
| ciof | Firmware | |
| CLHS | SysCfg | |
| CPRV | APTicket | Chip Revision |
| csys | ||
| dCfg | FDR | |
| dcpf | ||
| dcp2 | ||
| dtre | Firmware | Device Tree |
| eCfg | FDR, SysCfg | |
| ECID | ||
| EPRO | APTicket | |
| ESEC | ||
| fCfg | ||
| gfxf | Firmware | Graphics Firmware |
| ibdt | Firmware | iBoot Data |
| ibot | Firmware | iBoot |
| ispf | Firmware | Image Signal Processor Firmware |
| krnl | Firmware | XNU Kernel |
| ksku | ||
| kuid | Boot Policy | Key Exchange Key UUID |
| logo | Firmware | iBoot Apple Logo |
| love | Boot Policy | OS Version |
| lpnh | Boot Policy | LocalPolicy Nonce Hash |
| lpol | Firmware, Boot Policy | Local Policy |
| Mod# | FDR, SysCfg | Model Number |
| MOJO | SMC | Mojo Debug Flag |
| nsih | ||
| pmpf | Firmware | Power Management Processor Firmware |
| Regn | FDR, SysCfg | Region |
| rlg1 | Firmware | |
| rlg2 | Firmware | |
| rpnh | Boot Policy | Remote Policy Nonce Hash |
| roph | Boot Policy | RecoveryOS Policy Nonce Hash |
| seal | FDR | |
| SDOM | APTicket | Security Domain |
| siof | Firmware | Smart-IO Firmware |
| sip0 | Boot Policy | System Integrity Protection |
| sip1 | Boot Policy | System Integrity Protection |
| sip2 | Boot Policy | System Integrity Protection |
| sip3 | Boot Policy | System Integrity Protection |
| smb0 | Boot Policy | Secure Multi-Boot |
| smb1 | Boot Policy | Secure Multi-Boot |
| smb2 | Boot Policy | Secure Multi-Boot |
| smb3 | Boot Policy | Secure Multi-Boot |
| smb4 | Boot Policy | Secure Multi-Boot |
| SrNm | SysCfg | Serial Number |
| tCfg | FDR, SysCfg | |
| tmuf | Firmware | |
| WSKU | SysCfg | |
| vuid | Boot Policy | Volume UUID |