Directives and default values Optional value range Comment For example

{$ A8}
{$ ALIGN8}
{$A+},{$A-},
{$A1},{$A2},{$A4},{$A8};
{$ALIGN ON},{$ALIGN OFF},
{$ALIGN 1},{$ALIGN 2},
{$ALIGN 4},{$ALIGN 8}
Local
{$ APPTYPE GUI} {$APPTYPE GUI},
{$APPTYPE CONSOLE}
Global
{$B-}
{$BOOLEVAL OFF}
{$B+},{$B-};
{$BOOLEVAL ON},
{$BOOLEVAL OFF}
Local
{$C+}
{$ASSERTIONS ON}
{$C+},{$C-};
{$ASSERTIONS ON},
{$ASSERTIONS OFF}
Local
{$D+}
{$DEBUGINFO ON}
{$D+},{$D-}
{$DEBUGINFO ON},
{$DEBUGINFO OFF}
Global
{$DENYPACKAGEUNIT OFF} {$ DENYPACKAGEUNIT ON}, Local
{$DESCRIPTION ‘text’} Global
{$DESIGNONLY OFF} {$DESIGNONLY ON},
{$DESIGNONLY OFF}
Local
$ {E} {$ E +}, {$ E-}
{$E extension}
{$EXTENSION extension}
{$ EXTERNALSYM identifier}
{$F-} {$F+},{$F-}
{$FINITEFLOAT ON} {$FINITEFLOAT ON},
{$FINITEFLOAT OFF}
Global
{$G+}
{$IMPORTEDDATA ON}
{$G+},{$G-};
{$IMPORTEDDATA ON},
{$IMPORTEDDATA OFF}
Local
{$H+}
{$LONGSTRINGS ON}
{$H+},{$H-}
{$LONGSTRINGS ON},
{$LONGSTRINGS OFF}
Local
{$HINTS ON} {$HINTS ON},
{$HINTS OFF}
Local
{$HPPEMIT ‘string’}
{$I filename}
{$INCLUDE filename}
Local
{$I+}
{$IOCHECKS ON}
{$I+},{$I-};
{$IOCHECKS ON},
{$IOCHECKS OFF}
Local
{$IMAGEBASE $00400000} {$IMAGEBASE number} Global
{$IMPLICITBUILD ON},{$IMPLICITBUILD OFF} {$IMPLICITBUILD ON} Global
{$J-}
{$WRITEABLECONST OFF}
{$J+},{$J-}
{$WRITEABLECONST ON},
{$WRITEABLECONST OFF}
Local
{$ K-} {$ A +}, {K} $
{$L+}
{$LOCALSYMBOLS ON}
{$L+},{$L-}
{$LOCALSYMBOLS ON},
{$LOCALSYMBOLS OFF}
Global
{$L filename}
{$LINK filename}
Local
$LIBPREFIX ‘lib’ or $SOPREFIX ‘bpl’
$LIBSUFFIX ‘ ‘
$LIBVERSION ‘ ‘
$LIBPREFIX ‘string’
$LIBSUFFIX ‘string’
$LIBVERSION ‘string’
Global
{$M-}
{$TYPEINFO OFF}
{$M+},{$M-}
{$TYPEINFO ON},
{$TYPEINFO OFF}
Local
{$M 16384,1048576} {$ M minstacksize, maxstacksize};
{$ MINSTACKSIZE number}
{$ MAXSTACKSIZE number}
{$M 1048576} {$M reservedbytes}
{$RESOURCERESERVE reservedbytes}
Global Linux
{$MESSAGE HINT|WARN|ERROR|FATAL ‘text string’} Local
{$METHODINFO OFF} {$METHODINFO ON},
{$METHODINFO OFF}
{$N+} {$N+},{$N-}
{$ NODEFINE identifier}
{$NOINCLUDE filename}
{$O+}
{$OPTIMIZATION ON}
{$O+},{$O-};
{$OPTIMIZATION ON},
{$OPTIMIZATION OFF}
Local
{$ObjExportAll Off} {$ObjExportAll On},
{$ObjExportAll Off}
Global
{$P+}
{$OPENSTRINGS ON}
{$P+},{$P-}
{$OPENSTRINGS ON},
{$OPENSTRINGS OFF}
Local
{$POINTERMATH OFF} {$POINTERMATH ON},
{$POINTERMATH OFF}
Local
{$Q-}
{$OVERFLOWCHECKS OFF}
{$Q+},{$Q-}
{$OVERFLOWCHECKS ON},
{$OVERFLOWCHECKS OFF}
Local
{$R filename}
{$RESOURCE filename}
{$R *.xxx}
{$R filename.res filename.rc}
{$ R-}
{$ RANGECHECKS OFF}
{$ R +}, {$ R-}
{$ RANGECHECKS ON},
{$ RANGECHECKS OFF}
Local
{$REALCOMPATIBILITY OFF} {$REALCOMPATIBILITY ON},
{$REALCOMPATIBILITY OFF}
Local
{$RUNONLY OFF} {$RUNONLY ON},
{$RUNONLY OFF}
Local
{$S-} {$S+},{$S-}
{$SetPEFlags <integer expression>}
{$SetPEOptFlags <integer expression>}
Local
{$T-}
{$TYPEDADDRESS OFF}
{$T+},{$T-}
{$TYPEDADDRESS ON},
{$TYPEDADDRESS OFF}
Global
{$
U- } {$ SAFEDIVIDE OFF
{$U+},{$U-}
{$SAFEDIVIDE ON},
{$SAFEDIVIDE OFF}
Local
{$ V +}
{$ VARSTRINGCHECKS ON}
{$ V +}, {$ V-}
{$ VARSTRINGCHECKS ON},
{$ VARSTRINGCHECKS OFF}
Local
{$ W-}
{$ STACKFRAMES OFF}
{$ W +}, {$ W-}
{$ STACKFRAMES ON},
{$ STACKFRAMES OFF}
Local
{$WARN ON} {$WARN identifier ON},
{$WARN identifier OFF}
Local
{$WARNINGS ON} {$WARNINGS ON},
{$WARNINGS OFF}
Local
{$WEAKPACKAGEUNIT OFF} {$WEAKPACKAGEUNIT ON},
{$WEAKPACKAGEUNIT OFF}
Local
{$X+}
{$EXTENDEDSYNTAX ON}
{$X+},{$X-};
{$EXTENDEDSYNTAX ON},
{$EXTENDEDSYNTAX OFF}
Global
{$YD}
{$DEFINITIONINFO ON}
{$Y+},{$Y-},{$YD};
{$REFERENCEINFO ON},
{$REFERENCEINFO OFF};
{DEFINITIONINFO ON},
{DEFINITIONINFO OFF}
Global
{$Z1}
{$MINENUMSIZE 1}
{$Z1},{$Z2},{$Z4};
{$MINENUMSIZE 1},
{$MINENUMSIZE 2},
{$MINENUMSIZE 4}
Local
$DEFINE
$UNDEF$IFDEF
$ELSE
$ENDIF

{$IF DEFINED(…)}
{$IFEND}

{$IF NOT DEFINED(…)}
{$IFEND}

{$IF DEFINED(…) OR DEFINED(…)}
{$IFEND}

{$IF DEFINED(…) AND DEFINED(…)}
{$IFEND}

{$IF System.Const >= Number}
{$IFEND}

{$IFOPT …}
{$ELSE}
{$ENDIF}

{$region ‘text’} … {$endregion}

Delphi 2009, 2010 method to reduce file size:

// Add in the dpr file:
{$WEAKLINKRTTI ON}
{$RTTI EXPLICIT METHODS([]) PROPERTIES([]) FIELDS([])}