Update.

	* manual/creature.texi (Feature Test Macros): Mention _ISOC99_SOURCE.

1 files changed, 15 insertions, 5 deletions

diff --git a/manual/creature.texi b/manual/creature.texi
index befea10198..11061f9321 100644
--- a/manual/creature.texi
+++ b/manual/creature.texi
@@ -26,12 +26,12 @@ functions with names that smaller ones reserve to the user program.  This
 is not mere pedantry --- it has been a problem in practice.  For instance,
 some non-GNU programs define functions named @code{getline} that have
 nothing to do with this library's @code{getline}.  They would not be
-compilable if all features were enabled indescriminantly. 
+compilable if all features were enabled indescriminantly.
 
 This should not be used to verify that a program conforms to a limited
 standard.  It is insufficent for this purpose, as it will not protect you
 from including header files outside the standard, or relying on semantics
-undefined within the standard. 
+undefined within the standard.
 
 @comment (none)
 @comment POSIX.1
@@ -195,10 +195,20 @@ This macro was introduced as part of the Large File Support extension
 
 @comment (none)
 @comment GNU
+@defvr Macro _ISOC99_SOURCE
+Until the revides @w{ISO C} standard is widely adopted the new features
+are not automatically enabled.  The GNU libc nevertheless has a complete
+implementation of the new standard and to enable the new features the
+macro @code{_ISOC99_SOURCE} should be defined.
+@end defvr
+
+@comment (none)
+@comment GNU
 @defvr Macro _GNU_SOURCE
-If you define this macro, everything is included: @w{ISO C}, POSIX.1,
-POSIX.2, BSD, SVID, X/Open, LFS, and GNU extensions.  In the cases where
-POSIX.1 conflicts with BSD, the POSIX definitions take precedence.
+If you define this macro, everything is included: @w{ISO C89}, @w{ISO
+C99}, POSIX.1, POSIX.2, BSD, SVID, X/Open, LFS, and GNU extensions.  In
+the cases where POSIX.1 conflicts with BSD, the POSIX definitions take
+precedence.
 
 If you want to get the full effect of @code{_GNU_SOURCE} but make the
 BSD definitions take precedence over the POSIX definitions, use this