diff --git a/harbour/doc/codestyl.txt b/harbour/doc/codestyl.txt
index a70d7ca741..cb4b87da0e 100644
--- a/harbour/doc/codestyl.txt
+++ b/harbour/doc/codestyl.txt
@@ -161,6 +161,44 @@ Syntax and indentation
     consistency in indenture so that definitions, comments, and 
     control structures line up correctly.
 
+
 Documentation
 --------------
 
+[1] Whenever be possible document yourself functions you developed.
+    Usually is hard to understand code wrotted by other person, moreover
+    when it involve some obscure algorithm, system's vars or attributes
+    or data unavailable for the documentator.
+    This is particularly evident for low level functions.
+
+[2] After some time function was wrotted, work become more difficult because
+    it's need it to read the code several times (even for the own developer).
+    This is evident when variables don't have useful names (and uses only
+    letters).
+    Because that, please DO NOT leave functions without documentation.
+
+[3] If function made calls to other non-documented functions, and the 
+    original developer are not available anymore, could be so hard and even 
+    impossible to document it.
+
+[4] Tracking which functions are documented and which are not, and if they 
+    are total or partially documented are a waste of resources in time and 
+    people.
+
+[5] If you are the developer of the function don't worry by your narrative
+    skills, concentrate in what functions do, which arguments it gets, 
+    which are its purpose and specially what information function returns.
+
+[6] If you are the developer of the function, and you are using system's 
+    functions or vars undocumented, please explain it as much as possible.
+    If you use a obscure or strange algorithm (i.e md5 ) please explain what 
+    it does and how it works.
+
+[7] Notes, remarks and explainings enclose always between the /* */ pair, 
+    please don't use the double bar // because it difficults portability.
+
+[8] Remember... documentation it's a much time consuming work, usually
+    takes more time writing the documentation of a function that writing
+    the function itself.
+
+