diff --git a/extensions/_unitex.cpp b/extensions/_unitex.cpp
index 01b2737f15688c39478a2346edb5652f07ac6946..c2e3cd2f423d9895c27b08292349cc7aec5022e3 100644
--- a/extensions/_unitex.cpp
+++ b/extensions/_unitex.cpp
@@ -162,7 +162,7 @@ This function unloads a dictionary from persistent space.\n\n\
 Positional arguments (length: 1):\n\
     0 [str] -- the persistent file path returned by the\n\
                'load_persistent_dictionary' function.\n\n\
-Return [None]\
+Return [None].\
 ";
 static PyObject *unitex_free_persistent_dictionary(PyObject *self, PyObject *args);
 
@@ -182,7 +182,7 @@ This function unloads a grammar from persistent space.\n\n\
 Positional arguments (length: 1):\n\
     0 [str] -- the persistent file path returned by the\n\
                'load_persistent_fst2' function.\n\n\
-Return [None]\
+Return [None].\
 ";
 static PyObject *unitex_free_persistent_fst2(PyObject *self, PyObject *args);
 
@@ -202,7 +202,7 @@ This function unloads an alphabet from persistent space.\n\n\
 Positional arguments (length: 1):\n\
     0 [str] -- the persistent file path returned by the\n\
                'load_persistent_alphabet' function.\n\n\
-Return [None]\
+Return [None].\
 ";
 static PyObject *unitex_free_persistent_alphabet(PyObject *self, PyObject *args);
 
diff --git a/unitex/__init__.py b/unitex/__init__.py
index 2d4f97a95ec2f30190fc336a777457242993e582..7c38fce7b8f7604071b1537cbaa8a8581e660dfd 100644
--- a/unitex/__init__.py
+++ b/unitex/__init__.py
@@ -179,6 +179,35 @@ def disable_stderr():
 
 
 def init_log_system(verbose, debug, log=None):
+    """
+    This function enables/disables the logging system.
+
+    Arguments:
+        verbose [int] -- enables/disables the standard output. Possible
+            values are:
+            - 0: the standard output is disabled;
+            - 1: the standard output shows 'warnings' emitted by the
+                 bindings logging system.
+            - 2: the standard output shows 'warnings' and various
+                 processing informations emitted by the bindings logging
+                 system;
+            - 3: the full standard output is activated for both the
+                 bindings and the Unitex processor.
+
+        debug [int] --  enables/disables the error output. Possible
+            values are: 
+            - 0: the error output is disabled;
+            - 1: the error output is limited to the logging system
+                 implemented in the bindings;
+            - 2: the error output is activated for both the bindings
+                 and the Unitex processor.
+
+        log [str] -- if not None, the error and standard outputs are
+            redirected to the file specified by this argument. Be sure
+            to have write access to this file.
+
+    Return [None].
+    """
     for handler in logging.root.handlers[:]:
         logging.root.removeHandler(handler)
     kwargs = {}