diff --git a/doc/userdoc.org b/doc/userdoc.org
index e7fe896122d842402bad67c9118fdc22b4e9d8ee..e06853aecdb62e60a340120ecef5483f6d236806 100644
--- a/doc/userdoc.org
+++ b/doc/userdoc.org
@@ -721,7 +721,7 @@ view. One just have to keep in mind that, as it will be depicted
 after, high-level variables *are not mutable*: their values can be
 *replaced* by a new ones but *cannot be modified*.
 
-*** Implicit type conversions
+*** Implicit type conversions<<implicit-conversion>>
 
 In order to avoid ambiguities, in ~pugs~, there is *no implicit*
 conversion in general.
@@ -738,6 +738,21 @@ This will be detailed in section [[functions]] and [[tuples]]
 This means that all affectation, unary and binary operators are
 defined explicitly for supported types.
 
+Here is a table of implicit type conversion *when allowed*.
+
+| expected type | convertible types                              |
+|---------------+------------------------------------------------|
+| ~N~             | ~B~, ~Z~                                           |
+| ~Z~             | ~B~, ~N~                                           |
+| ~R~             | ~B~, ~N~, ~Z~                                        |
+| ~R^1~           | ~B~, ~N~, ~Z~, ~R~, ~0~ (special value)                  |
+| ~R^2~           | ~0~ (special value)                              |
+| ~R^3~           | ~0~ (special value)                              |
+| ~R^1x1~         | ~B~, ~N~, ~Z~, ~R~, ~0~ (special value)                  |
+| ~R^2x2~         | ~0~ (special value)                              |
+| ~R^3x3~         | ~0~ (special value)                              |
+| ~string~        | ~B~, ~N~, ~Z~, ~R~, ~R^1~, ~R^2~, ~R^3~, ~R^1x1~, ~R^2x2~, ~R^3x3~ |
+
 *** Operators
 
 **** Affectation operators
@@ -1750,8 +1765,9 @@ data of a *unique* and *simple* type (one cannot use compound types to
 define tuples).
 
 The list of values given to the tuple must be *implicitly* convertible
-to the type of tuple elements. There is no ambiguity, the implicit
-conversions follow the rules of operator ~=~.
+to the type of tuple elements (see the conversion table in section
+[[implicit-conversion]]). There is no ambiguity, the implicit conversions
+follow the rules of operator ~=~.
 
 **** Tuple declaration and affectation
 
@@ -2097,7 +2113,12 @@ modified value is not a variable of the language itself but the
 internal random seed itself.
 #+END_note
 
-*** TODO Implicit type conversion for parameters and returned values
+*** Implicit type conversion for parameters and returned values
+
+As already said, in general, there is no implicit type conversion in
+the ~pugs~ language. The only exceptions are when initializing tuples
+(see [[tuples]]) and for functions arguments and returned values.  See the
+conversion table in section [[implicit-conversion]].
 
 *** User-defined functions<<user-defined-functions>>