| ConfigExtension | Default application configuration file extension. | 
| CPUEndian | Current CPU endianness | 
| DateDelta | Days between 1/1/0001 and 12/31/1899 | 
| DriveDelim | Drive letter delimiter | 
| EmptyStr | Empty String Constant | 
| EmptyWideStr | Empty wide string. | 
| faAnyFile | Match any file | 
| faArchive | Archive bit is set | 
| faCompressed | Compressed file attribute | 
| faDirectory | File is a directory | 
| faEncrypted | Encrypted file attribute | 
| faHidden | Hidden file. | 
| faNormal | Normal file attribute | 
| faReadOnly | Read-Only file. | 
| faSymLink | File is a symlink | 
| faSysFile | System file (Dos/Windows only) | 
| faTemporary | Temporary file attribute | 
| faVirtual | Virtual file attribute | 
| faVolumeId | Volume id (Fat file system, Dos/Windows only) | 
| feInvalidHandle | FileOpen error value | 
| fmOpenRead | Open file in read-only mode | 
| fmOpenReadWrite | Open file in read/write mode. | 
| fmOpenWrite | Open file in write-only mode | 
| fmShareCompat | Open file in DOS share-compatibility mode | 
| fmShareDenyNone | Do not lock file. | 
| fmShareDenyRead | Lock file so other processes cannot read. | 
| fmShareDenyWrite | Lock file so other processes can only read. | 
| fmShareExclusive | Lock file for exclusive use | 
| fsFromBeginning | Start seek operation from beginning of file. | 
| fsFromCurrent | Start seek operation from current position in file. | 
| fsFromEnd | Start seek operation from end of file. | 
| GUID_NULL | NULL GUID constant | 
| HexDisplayPrefix | String to prepend to hexadecimal values | 
| HoursPerDay | Number of hours in a day. | 
| JulianEpoch | Starting point of the Julian calendar | 
| LeadBytes | Lead bytes in Multi-Byte character sets | 
| MaxCurrency | Maximum currency value | 
| MaxDateTime | Maximum TDateTime value. | 
| MAX_PATH | Maximum length of a fully qualified filename (including path) | 
| MinCurrency | Minimum Currency value | 
| MinDateTime | Minimum TDateTime value. | 
| MinsPerDay | Number of minutes per day. | 
| MinsPerHour | Number of minutes per hour. | 
| MonthDays | Array with number of days in the months for leap and non-leap years. | 
| MSecsPerDay | Number of milliseconds per day | 
| MSecsPerSec | Number of milliseconds per second | 
| NullStr | Pointer to an empty string | 
| PathDelim | Path (directory) delimiter. | 
| PathSep | Path separator. (Separates paths in search path lists) | 
| pfBCB4Produced | Not used in Free Pascal. | 
| pfDelphi4Produced | Not used in Free Pascal. | 
| pfDesignOnly | Package is a design-time only package | 
| pfExeModule | Package is an executable | 
| pfIgnoreDupUnits | Ignore duplicate units in package | 
| pfLibraryModule | Package is a library | 
| pfModuleTypeMask | Mask for module type flags | 
| pfNeverBuild | Never-build flag was specified when compiling package | 
| pfPackageModule | Package is a real package (not exe) | 
| pfProducerMask | Mask for producer flags | 
| pfProducerUndefined | Not used in Free Pascal. | 
| pfRunOnly | Package is a run-time only package | 
| pfV3Produced | Not used in Free Pascal. | 
| RTL_SIGBUS | Bus error signal number (Unix only) | 
| RTL_SIGDEFAULT | Default signal handler (Unix only) | 
| RTL_SIGFPE | Floating Point Error signal number (Unix only) | 
| RTL_SIGILL | Illegal instruction signal number (Unix only) | 
| RTL_SIGINT | INTERRUPT signal number (Unix only) | 
| RTL_SIGLAST | Last signal number (Unix only) | 
| RTL_SIGQUIT | QUIT signal number (Unix only) | 
| RTL_SIGSEGV | Segmentation fault signal number (Unix only) | 
| SecsPerDay | Number of seconds per day | 
| SecsPerHour |  | 
| SecsPerMin | Number of seconds per minute | 
| SwitchChars | Characters which start a command-line switch | 
| SysConfigDir | System configuration directory. | 
| ufImplicitUnit | Unit was implicitly imported into package (did not appear in package contains list) | 
| ufMainUnit | Unit is the main unit of the package | 
| ufOrgWeakUnit | Unit is the original weak packaged unit | 
| ufPackageUnit | Unit is a packaged unit (appeared in package contains list) | 
| ufWeakPackageUnit | Weak (original or not) packaged unit | 
| ufWeakUnit | Unit is a weak packaged unit | 
| UnixDateDelta | Number of days between 1.1.1900 and 1.1.1970 | 
| UnixEpoch | Starting point of the unix calendar (1/1/1970) |