I don't see SO3 being used anywhere

set_soenv.in

@@ -46,7 +46,7 @@ my ( $oldoutfile, $outfile, $bootfile, $newline, $comment,
 #
 # Platform independent constant values.
 my ( $CALL_CDECL, $COMMON_OUTDIR,
-     $common_build, $NO_REC_RES, $SO3, $SOLAR_JAVA,
+     $common_build, $NO_REC_RES, $SOLAR_JAVA,
      $SOLAR_PLUGIN, $UPDATER, $VCL,
      $CC, $CXX,
      $NO_BSYMBOLIC);
@@ -170,7 +170,6 @@ $CALL_CDECL           = "TRUE";
 $COMMON_OUTDIR        = "";
 $common_build         = "";
 $NO_REC_RES           = "TRUE";
-$SO3                  = "TRUE";
 $SOLAR_JAVA           = "@SOLAR_JAVA@";
 $SOLAR_PLUGIN         = "TRUE";
 $UPDATER              = "YES";
@@ -1443,7 +1442,6 @@ ToFile( "CALL_CDECL",        $CALL_CDECL,        "e" );
 ToFile( "COMMON_OUTDIR",     $COMMON_OUTDIR,     "e" );
 ToFile( "common_build",      $common_build,      "e" );
 ToFile( "NO_REC_RES",        $NO_REC_RES,        "e" );
-ToFile( "SO3",               $SO3,               "e" );
 ToFile( "SOLAR_PLUGIN",      $SOLAR_PLUGIN,      "e" );
 ToFile( "UPDATER",           $UPDATER,           "e" );
 ToFile( "VCL",               $VCL,               "e" );

solenv/inc/startup/startup.mk

@@ -33,7 +33,7 @@ CALLTARGETS=$(MAKETARGETS)
 .INCLUDEDIRS : $(DMAKE_INC) $(SOLARVERSION)$/$(INPATH)$/inc $(SOLARENV)$/inc
 
 # Grab key definitions from the environment
-# .IMPORT .IGNORE : OS TMPDIR UPD INPATH OUTPATH GUI COM EX CLASSPATH PRODUCT GUIBASE SOLARENV SOLARVER GUIENV CPU CPUNAME GVER COMPATH LIB INCLUDE TR SORT UNIQ ROOTDIR SED AWK TOUCH IENV ILIB PRODUCT_ENV COMEX UPD BUILD DEVROOT VCL SO3 ENVCFLAGS
+# .IMPORT .IGNORE : OS TMPDIR UPD INPATH OUTPATH GUI COM EX CLASSPATH PRODUCT GUIBASE SOLARENV SOLARVER GUIENV CPU CPUNAME GVER COMPATH LIB INCLUDE TR SORT UNIQ ROOTDIR SED AWK TOUCH IENV ILIB PRODUCT_ENV COMEX UPD BUILD DEVROOT VCL ENVCFLAGS
 
 .IF "$(OS)" == "" || "$(OS)" == "Windows_NT"
 .ERROR : ; @echo Forced error: Environment variable OS has to be set for OOo build!