rtbuf/rtbuf

diff --git a/README.txt b/README.txt
index 05958fa..1643264 100644
--- a/README.txt
+++ b/README.txt
@@ -12,14 +12,21 @@ A real time function is made of :
   an optional start method that will be called before computation starts
   an optional compute method that will be called in real time
   an optional stop method that will be called after computation finishes
-  size and count of buffer members for memory allocation
-  variable names that can be bound to other buffers
+  variable definitions which are made of a name and a type designator
+  output definitions which are made of a name and a type designator
 
 Your library has to export specific symbols :
   rtbuf_lib_name  the name of your library
   rtbuf_lib_ver   an unsigned long used to verify binary compatiblity
   rtbuf_lib_fun   an array of library function definitions
 
+Optional symbols :
+  rtbuf_lib_init  a function to initialize the library
+
+When creating a new buffer from a real time function the outputs are
+allocated into buffer->data. When writing library functions please make
+sure the size of the types in your code matches the size of rtbuf types.
+
 The buffers are ordered according to bindings and real time computation
 can start. For each tick all buffers are computed.