| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y |
| jrand48 | jrand48_r |
| kerneldefs | key_t | killpg |
| kernelioctl | kill | klogctl |
| QCMD | quad_t | Q_QUOTAON |
| qecvt | QUEUE_FULL | Q_RSQUASH |
| qecvt_r | quotactl | Q_SETQLIM |
| qelem | QUOTAFILENAME | Q_SETQUOTA |
| qfcvt | QUOTAGROUP | Q_SETUSE |
| qfcvt_r | Q_GETQUOTA | Q_SYNC |
| qgcvt | Q_GETSTATS | |
| qsort | Q_QUOTAOFF |
| Word | Byte | updwtmpx |
| dword | UINT_LEAST16_MAX | useconds_t |
| QWord | Word | USER_PROCESS |
| Byte | UINT_LEAST32_MAX | Word |
| ualarm | dword | USHRT_MAX |
| UCHAR_MAX | UINT_LEAST64_MAX | usleep |
| ucontext | QWord | USRQUOTA |
| ucontext_t | UINT_LEAST8_MAX | ustat |
| ucred | Byte | utimbuf |
| udphdr | UINT_MAX | utime |
| uid_t | UIO_MAXIOV | utimes |
| dword | UI_CMD | utmp |
| UINT16_MAX | ulckpwdf | utmpname |
| Word | ulimit | utmpx |
| UINT32_MAX | ULLONG_MAX | utmpxname |
| dword | dword | UTMPX_FILE |
| UInt64 | ULONG_MAX | UTMPX_FILENAME |
| UINT64_MAX | UL_GETFSIZE | UTMP_FILE |
| QWord | UL_SETFSIZE | UTMP_FILENAME |
| UINT8_MAX | umask | utsname |
| Byte | Word | UT_HOSTSIZE |
| UINTMAX_MAX | umount | UT_LINESIZE |
| QWord | umount2 | UT_NAMESIZE |
| UINTPTR_MAX | uname | UT_UNKNOWN |
| dword | ungetc | u_char |
| UINT_FAST16_MAX | ungetwc | u_int |
| dword | UNIT_ATTENTION | Word |
| UINT_FAST32_MAX | UNKNOWN_REQUEST | dword |
| dword | unlink | Byte |
| UINT_FAST64_MAX | unlockpt | u_long |
| QWord | unsetenv | u_quad_t |
| UINT_FAST8_MAX | updwtmp | u_short |
| X86_FXSR_MAGIC | XTABS | |
| XCASE | X_OK |