diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 9be00483bc..51725baff8 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,7 @@
+2001-12-20  Jim Blandy  <jimb@redhat.com>
+
+	* gdbint.texinfo (TARGET_CHAR_SIGNED): Document.
+
 2001-12-15  Andrew Cagney  <ac131313@redhat.com>
 
 	* gdbint.texinfo (Target Architecture Definition): Replace
diff --git a/gdb/doc/gdbint.texinfo b/gdb/doc/gdbint.texinfo
index cf0d9301d1..8c4e73966a 100644
--- a/gdb/doc/gdbint.texinfo
+++ b/gdb/doc/gdbint.texinfo
@@ -3501,6 +3501,17 @@ Non-zero if the target has both @code{BIG_ENDIAN} and
 @findex TARGET_CHAR_BIT
 Number of bits in a char; defaults to 8.
 
+@item TARGET_CHAR_SIGNED
+@findex TARGET_CHAR_SIGNED
+Non-zero if @code{char} is normally signed on this architecture; zero if
+it should be unsigned.
+
+The ISO C standard requires the compiler to treat @code{char} as
+equivalent to either @code{signed char} or @code{unsigned char}; any
+character in the standard execution set is supposed to be positive.
+Most compilers treat @code{char} as signed, but @code{char} is unsigned
+on the IBM S/390, RS6000, and PowerPC targets.
+
 @item TARGET_COMPLEX_BIT
 @findex TARGET_COMPLEX_BIT
 Number of bits in a complex number; defaults to @code{2 * TARGET_FLOAT_BIT}.