The feature is less revelant to encoding conversion indeed

Author: Moriyoshi Koizumi

ext/gd/config.m4

@@ -40,8 +40,8 @@ PHP_ARG_WITH(t1lib, for T1lib support,
 PHP_ARG_ENABLE(gd-native-ttf, whether to enable truetype string function in GD,
 [  --enable-gd-native-ttf    GD: Enable TrueType string function.], no, no)
 
-PHP_ARG_ENABLE(gd-jis-conv, whether to enable japanese encoding conversion in GD,
-[  --enable-gd-jis-conv      GD: Enable Japanese encoding conversion.], no, no)
+PHP_ARG_ENABLE(gd-jis-conv, whether to enable JIS-mapped Japanese font support in GD,
+[  --enable-gd-jis-conv      GD: Enable JIS-mapped Japanese font suppert.], no, no)
 
 dnl  
 dnl Checks for the configure options