diff --git a/plugins/alias.py b/plugins/alias.py
index 163e4c26..4d4a3bf4 100644
--- a/plugins/alias.py
+++ b/plugins/alias.py
@@ -6,7 +6,7 @@ Allows the creation and the removal of personal aliases.
 
 from plugin import BasePlugin
 import common
-from common import parse_command_args_to_alias as parse
+from common import shell_split
 
 class Plugin(BasePlugin):
     def init(self):
@@ -27,18 +27,18 @@ class Plugin(BasePlugin):
         """
         arg = common.shell_split(line)
         if len(arg) < 2:
-            self.core.information('Alias: Not enough parameters', 'Error')
+            self.api.information('Alias: Not enough parameters', 'Error')
             return
         alias = arg[0]
         command = arg[1]
         tmp_args = arg[2] if len(arg) > 2 else ''
 
         if alias in self.core.commands or alias in self.commands:
-            self.core.information('Alias: command already exists', 'Error')
+            self.api.information('Alias: command already exists', 'Error')
             return
-        self.commands[alias] = lambda arg: self.get_command(command)(parse(arg, tmp_args))
+        self.commands[alias] = lambda arg: self.get_command(command)(tmp_args.format(*shell_split(arg)))
         self.add_command(alias, self.commands[alias], 'This command is an alias for /%s %s' %( command, tmp_args))
-        self.core.information('Alias /%s successfuly created' % alias, 'Info')
+        self.api.information('Alias /%s successfuly created' % alias, 'Info')
 
     def command_unalias(self, alias):
         """
@@ -47,7 +47,7 @@ class Plugin(BasePlugin):
         if alias in self.commands:
             del self.commands[alias]
             self.del_command(alias)
-            self.core.information('Alias /%s successfuly deleted' % alias, 'Info')
+            self.api.information('Alias /%s successfuly deleted' % alias, 'Info')
 
     def completion_unalias(self, the_input):
         aliases = [alias for alias in self.commands]
@@ -61,6 +61,6 @@ class Plugin(BasePlugin):
             pass
         if name in self.core.commands:
             return self.core.commands[name][0]
-        elif name in self.core.current_tab().commands:
-            return self.core.current_tab().commands[name][0]
+        elif name in self.api.current_tab().commands:
+            return self.api.current_tab().commands[name][0]
         return dummy
diff --git a/src/common.py b/src/common.py
index e4e3a52d..1a3027e7 100644
--- a/src/common.py
+++ b/src/common.py
@@ -6,7 +6,7 @@
 # it under the terms of the zlib license. See the COPYING file.
 
 """
-various useful functions
+Various useful functions.
 """
 
 from datetime import datetime, timedelta
@@ -29,6 +29,13 @@ ROOM_STATE_HL = 13
 def get_base64_from_file(path):
     """
     Convert the content of a file to base64
+
+    :param str path: The path of the file to convert.
+    :return: A tuple of (encoded data, mime type, sha1 hash) if
+        the file exists and does not exceeds the upper size limit of 16384.
+    :return: (None, None, error message) if it fails
+    :rtype: :py:class:`tuple`
+
     """
     if not os.path.isfile(path):
         return (None, None, "File does not exist")
@@ -44,7 +51,11 @@ def get_base64_from_file(path):
 
 def get_output_of_command(command):
     """
-    Runs a command and returns its output
+    Runs a command and returns its output.
+
+    :param str command: The command to run.
+    :return: The output or None
+    :rtype: :py:class:`str`
     """
     try:
         return subprocess.check_output(command.split()).decode('utf-8').split('\n')
@@ -53,9 +64,14 @@ def get_output_of_command(command):
 
 def is_in_path(command, return_abs_path=False):
     """
-    Return True if 'command' is found in one of the directories in the user's
-    path. If 'return_abs_path' is True, return the absolute path of the first
-    found command instead. Return False otherwise and on errors
+    Check if *command* is in the $PATH or not.
+
+    :param str command: The command to be checked.
+    :param bool return_abs_path: Return the absolute path of the command instead
+        of True if the command is found.
+    :return: True if the command is found, the command path if the command is found
+        and *return_abs_path* is True, otherwise False.
+
     """
     for directory in os.getenv('PATH').split(os.pathsep):
         try:
@@ -95,6 +111,8 @@ def get_os_info():
     """
     Returns a detailed and well formated string containing
     informations about the operating system
+
+    :rtype: str
     """
     if os.name == 'posix':
         executable = 'lsb_release'
@@ -151,14 +169,21 @@ def get_os_info():
 
 def datetime_tuple(timestamp):
     """
-    Convert timestamp using strptime and the format: %Y%m%dT%H:%M:%S
+    Convert a timestamp using strptime and the format: %Y%m%dT%H:%M:%S.
 
-    Because of various datetime formats are used the following exceptions
+    Because various datetime formats are used, the following exceptions
     are handled:
-            - Optional milliseconds appened to the string are removed
-            - Optional Z (that means UTC) appened to the string are removed
-            - XEP-082 datetime strings have all '-' cahrs removed to meet
-              the above format.
+
+    * Optional milliseconds appened to the string are removed
+    * Optional Z (that means UTC) appened to the string are removed
+    * XEP-082 datetime strings have all '-' chars removed to meet the above format.
+
+    :param str timestamp: The string containing the formatted date.
+    :return: The date.
+    :rtype: :py:class:`datetime.datetime`
+
+    >>> common.datetime_tuple('20130226T06:23:12')
+    datetime.datetime(2013, 2, 26, 8, 23, 12)
     """
     timestamp = timestamp.split('.')[0]
     timestamp = timestamp.replace('-', '')
@@ -172,6 +197,17 @@ def datetime_tuple(timestamp):
     return ret
 
 def shell_split(st):
+    """
+    Split a string correctly according to the quotes
+    around the elements.
+
+    :param str st: The string to split.
+    :return: A list of the different of the string.
+    :rtype: :py:class:`list`
+
+    >>> shell_split('"sdf 1" "toto 2"')
+    ['sdf 1', 'toto 2']
+    """
     sh = shlex.shlex(st, posix=True)
     sh.commenters = ''
     sh.whitespace_split = True
@@ -188,7 +224,12 @@ def shell_split(st):
 
 def parse_str_to_secs(duration=''):
     """
-    Parse a string of with a number of d, h, m, s
+    Parse a string of with a number of d, h, m, s.
+
+    :param str duration: The formatted string.
+    :return: The number of seconds represented by the string
+    :rtype: :py:class:`int`
+
     >>> parse_str_to_secs("1d3m1h")
     90180
     """
@@ -210,8 +251,15 @@ def parse_str_to_secs(duration=''):
 
 def parse_secs_to_str(duration=0):
     """
+    Do the reverse operation of :py:func:`parse_str_to_secs`.
+
     Parse a number of seconds to a human-readable string.
     The string has the form XdXhXmXs. 0 units are removed.
+
+    :param int duration: The duration, in seconds.
+    :return: A formatted string containing the duration.
+    :rtype: :py:class:`str`
+
     >>> parse_secs_to_str(3601)
     1h1s
     """
@@ -230,36 +278,13 @@ def parse_secs_to_str(duration=0):
         result = '0s'
     return result
 
-def parse_command_args_to_alias(arg, strto):
-    """
-    Parse command parameters.
-    Numbers can be from 0 to 9.
-    >>> parse_command_args_to_alias('sdf koin', '%1 %0')
-    "koin sdf"
-    """
-    if '%' not in strto:
-        return strto + arg
-    args = shell_split(arg)
-    l = len(args)
-    dest = ''
-    var_num = False
-    for i in strto:
-        if i != '%':
-            if not var_num:
-                dest += i
-            elif i in string.digits:
-                if 0 <= int(i) < l:
-                    dest += args[int(i)]
-                var_num = False
-        elif i == '%':
-            if var_num:
-                dest += '%'
-                var_num = False
-            else:
-                var_num = True
-    return dest
-
 def safeJID(*args, **kwargs):
+    """
+    Construct a :py:class:`sleekxmpp.JID` object from a string.
+
+    Used to avoid tracebacks during is stringprep fails
+    (fall back to a JID with an empty string).
+    """
     try:
         return JID(*args, **kwargs)
     except InvalidJID:
diff --git a/src/plugin.py b/src/plugin.py
index 602d0326..2ef83510 100644
--- a/src/plugin.py
+++ b/src/plugin.py
@@ -6,6 +6,7 @@ These are used in the plugin system added in poezio 0.7.5
 import os
 from functools import partial
 from configparser import RawConfigParser
+from timed_events import TimedEvent, DelayedEvent
 import config
 import inspect
 import traceback
@@ -120,12 +121,49 @@ class PluginAPI(object):
 
     def add_timed_event(self, _, *args, **kwargs):
         """
-        Add a timed event.
+        Schedule a timed event.
 
-        :param event: The timed event to add.
+        :param timed_events.TimedEvent event: The timed event to schedule.
         """
         return self.core.add_timed_event(*args, **kwargs)
 
+    def remove_timed_event(self, _, *args, **kwargs):
+        """
+        Unschedule a timed event.
+
+        :param timed_events.TimedEvent event: The event to unschedule.
+        """
+        return self.core.remove_timed_event(*args, **kwargs)
+
+    def create_timed_event(self, _, *args, **kwargs):
+        """
+        Create a timed event, but do not schedule it;
+        :py:func:`~PluginAPI.add_timed_event` must be used for that.
+
+        :param datetime.datetime date: The time at which the handler must be executed
+        :param function callback: The handler that will be executed
+        :param \*args: Optional arguments passed to the handler.
+        :return: The created event.
+        :rtype: :py:class:`timed_events.TimedEvent`
+        """
+        return TimedEvent(*args, **kwargs)
+
+    def create_delayed_event(self, _, *args, **kwargs):
+        """
+        Create a delayed event, but do not schedule it;
+        :py:func:`~PluginAPI.add_timed_event` must be used for that.
+
+        A delayed event is a timed event with a delay from the time
+        this function is called (instead of a datetime).
+
+        :param int delay: The number of seconds to schedule the execution
+        :param function callback: The handler that will be executed
+        :param \*args: Optional arguments passed to the handler.
+        :return: The created event.
+        :rtype: :py:class:`timed_events.DelayedEvent`
+        """
+        return DelayedEvent(*args, **kwargs)
+
     def information(self, _, *args, **kwargs):
         """
         Display a new message in the information buffer.
@@ -139,7 +177,7 @@ class PluginAPI(object):
         """
         Get the current Tab.
 
-        :returns: tabs.Tab The current tab.
+        :returns: The current tab.
         """
         return self.core.current_tab()
 
@@ -176,7 +214,7 @@ class PluginAPI(object):
 
             Example string: "<server> [port]"
 
-        :raises: Exception If the command already exists.
+        :raises Exception: If the command already exists.
         """
         return self.plugin_manager.add_command(module, *args, **kwargs)
 
diff --git a/src/timed_events.py b/src/timed_events.py
index 5be2aba2..a922ee03 100644
--- a/src/timed_events.py
+++ b/src/timed_events.py
@@ -6,8 +6,11 @@
 # it under the terms of the zlib license. See the COPYING file.
 
 """
-To use these, just use core.add_timed_event(event)
-where event is an instance of one of these classes
+Timed events are the standard way to schedule events for later in poezio.
+
+Once created, they must be added to the list of checked events with
+:py:func:`Core.add_timed_event` (within poezio) or with
+:py:func:`.PluginAPI.add_timed_event` (within a plugin).
 """
 
 import logging
@@ -18,13 +21,22 @@ import datetime
 
 class TimedEvent(object):
     """
-    An event with a callback that is called when the specified time is passed
+    An event with a callback that is called when the specified time is passed.
+
     Note that these events can NOT be used for very small delay or a very
     precise date, since the check for events is done once per second, as
     a maximum.
+
     The callback and its arguments should be passed as the lasts arguments.
     """
     def __init__(self, date, callback, *args):
+        """
+        Create a new timed event.
+
+        :param datetime.datetime date: Time at which the callback must be run.
+        :param function callback: The handler that will be executed.
+        :param \*args: Optional arguments passed to the handler.
+        """
         self._callback = callback
         self.args = args
         self.repetive = False
@@ -42,7 +54,11 @@ class TimedEvent(object):
 
     def has_timed_out(self, current_date):
         """
-        returns True if the callback should be called
+        Check if the event has timed out.
+
+        :param datetime.datetime current_date: The current date.
+        :returns: True if the callback should be called
+        :rtype: bool
         """
         if self.next_call_date < current_date:
             return True
@@ -51,22 +67,33 @@ class TimedEvent(object):
 
     def change_date(self, date):
         """
-        Simply change the date of the event
+        Simply change the date of the event.
+
+        :param datetime.datetime date: Next date.
         """
         self.next_call_date = date
 
     def add_delay(self, delay):
         """
-        Add a delay (in seconds) to the date
+        Add a delay (in seconds) to the date.
+
+        :param int delay: The delay to add.
         """
         self.next_call_date += datetime.timedelta(seconds=delay)
 
 class DelayedEvent(TimedEvent):
     """
-    The date is calculated from now + a delay in seconds
-    Use it if you want an event to happen in, e.g. 6 seconds
+    A TimedEvent, but with the date calculated from now + a delay in seconds.
+    Use it if you want an event to happen in, e.g. 6 seconds.
     """
     def __init__(self, delay, callback, *args):
+        """
+        Create a new DelayedEvent.
+
+        :param int delay: The number of seconds.
+        :param function callback: The handler that will be executed.
+        :param \*args: Optional arguments passed to the handler.
+        """
         date = datetime.datetime.now() + datetime.timedelta(seconds=delay)
         TimedEvent.__init__(self, date, callback, *args)