--- a/README	Mon Oct 02 17:57:46 2000 +0200
+++ b/README	Fri Oct 27 15:17:27 2000 +0200
@@ -20,3 +20,12 @@
 If you want to use it in your programs, you may try to figure out how
 by reading the header files (include/*.h) and test programs (tester*.c).
 Or you could try urging me to write some sort of a manual.
+
+---
+
+Libtu needs the functions asprintf and vasprintf. These do not
+exist on most platforms. One implementation is available at
+<http://www.ijs.si/software/snprintf/>, which is used by default
+and is supposed to be found at ../snprintf_2.2. To use the
+system's versions, if available, modify system.mk.
+