diff --git a/doc/developer-guide.md b/doc/developer-guide.md
index 70e3a4dd..23f1af11 100644
--- a/doc/developer-guide.md
+++ b/doc/developer-guide.md
@@ -23,8 +23,10 @@ The `core` module is responsible for:
 
 - creating the layout (using [UI Layout][4])
 - creating the editor (using [PageDown][5])
-- Loading/saving the settings
-- detecting the offline status
+- loading/saving the settings
+- running period tasks
+- detecting the user activity
+- checking the offline status
 
 
 ----------
@@ -34,9 +36,29 @@ The `core` module is responsible for:
 
 The `fileMgr` module is responsible for:
 
-- creating/deleting local files
+- creating and deleting local files
 - switching from one file to another
-- setting/removing file's sync/publish location
+
+#### FileDescriptor
+
+The `FileDescriptor` class represents a local file. A `FileDescriptor` object has the following properties:
+
+- `fileIndex`: the unique string index of the file in the file system
+- `title`: the title of the document
+- `content`: the content of the document
+- `syncLocations`: a map containing all the associated [`syncAttributes`][7] objects with their `syncIndex` as a key
+- `publishLocations`: a map containing all the associated [`publishAttributes`][8] objects with their `publishIndex` as a key
+
+And the following methods:
+
+- `addSyncLocation(syncAttributes)`: associates a [`syncAttributes`][9] object with the file
+- `removeSyncLocation(syncAttributes)`: unassociates a [`syncAttributes`][10] object with the file
+- `addPublishLocation(publishAttributes)`: associates a [`publishAttributes`][11] object with the file
+- `removePublishLocation(publishAttributes)`: unassociates a [`publishAttributes`][12] object with the file
+
+#### fileSystem
+
+The `fileSystem` module is a map containing all the [`FileDescriptor`][6] objects with their `fileIndex` as a key
 
 
 ----------
@@ -50,6 +72,22 @@ The `synchronizer` module is responsible for:
 - creating a new sync location from a local file (export)
 - running 2 ways synchronization (upload and download) for all sync locations
 
+#### synchronizer's providers
+
+A [`provider`][13] module can be associated with the `synchronizer` module if it implements the following functions:
+
+- `importFiles()`: downloads one or multiple files and create local files associated with the sync locations
+- `exportFile()`: uploads a local file to a new sync location
+- `syncDown()`: performs a download of all the changes operated on all sync locations
+- `syncUp()`: performs an upload of a change to a sync location
+
+#### syncAttributes
+
+A `syncAttributes` object is an object that describes a sync location. Attributes differ from one provider to another except for the following:
+
+- `syncIndex`: the unique string index of the publish location
+- `provider`: the [`provider`][14] module that handles the sync location
+
 
 ----------
 
@@ -63,17 +101,17 @@ The `publisher` module is responsible for:
 
 #### publisher's providers
 
-A [`provider`][6] module can be associated with the `publisher` module if it implements the following functions:
+A [`provider`][15] module can be associated with the `publisher` module if it implements the following functions:
 
-- `newPublishAttributes()`: returns a new [`publishAttributes`][7] object in order to create a new publish location
+- `newPublishAttributes()`: returns a new [`publishAttributes`][16] object in order to create a new publish location
 - `publish()`: performs publishing of one publish location
 
 #### publishAttributes
 
-A `publishAttributes` object is an object that describes a publish location. Attributes list differs from one provider to another except for the following attributes:
+A `publishAttributes` object is an object that describes a publish location. Attributes differ from one provider to another except for the following:
 
-- `publishIndex`: the unique index of the publish location
-- `provider`: the [`provider`][6] module that handles the publish location
+- `publishIndex`: the unique string index of the publish location
+- `provider`: the [`provider`][17] module that handles the publish location
 - `format`: the publishing format for the publish location. It can be:
 	- `markdown` for Markdown format
 	- `html` for HTML format
@@ -98,5 +136,15 @@ A `publishAttributes` object is an object that describes a publish location. Att
   [3]: http://en.wikipedia.org/wiki/Asynchronous_module_definition "Asynchronous module definition"
   [4]: http://layout.jquery-dev.net/ "UI Layout"
   [5]: https://code.google.com/p/pagedown/ "PageDown"
-  [6]: #provider
-  [7]: #publishattributes
\ No newline at end of file
+  [6]: #filedescriptor
+  [7]: #syncattributes
+  [8]: #publishattributes
+  [9]: #syncattributes
+  [10]: #syncattributes
+  [11]: #publishattributes
+  [12]: #publishattributes
+  [13]: #provider
+  [14]: #provider
+  [15]: #provider
+  [16]: #publishattributes
+  [17]: #provider
\ No newline at end of file