diff --git a/src/fs_image.c b/src/fs_image.c
index 6f9c1f6..e16e747 100644
--- a/src/fs_image.c
+++ b/src/fs_image.c
@@ -1663,6 +1663,7 @@ int iso_image_filesystem_new(IsoDataSource *src, struct iso_read_opts *opts,
         goto fs_cleanup;
     }
 
+    strncpy(ifs->type, "iso ", 4);
     ifs->data = data;
     ifs->refcount = 1;
     ifs->get_root = ifs_get_root;
diff --git a/src/fs_image.h b/src/fs_image.h
index 88bb0b1..1f69cea 100644
--- a/src/fs_image.h
+++ b/src/fs_image.h
@@ -24,22 +24,58 @@ typedef IsoFilesystem IsoImageFilesystem;
 int iso_image_filesystem_new(IsoDataSource *src, struct iso_read_opts *opts,
                              int msgid, IsoImageFilesystem **fs);
 
+/**
+ * Get the volset identifier for an existent image. The returned string belong
+ * to the IsoImageFilesystem and shouldn't be free() nor modified.
+ */
 const char *iso_image_fs_get_volset_id(IsoImageFilesystem *fs);
 
+/**
+ * Get the volume identifier for an existent image. The returned string belong
+ * to the IsoImageFilesystem and shouldn't be free() nor modified.
+ */
 const char *iso_image_fs_get_volume_id(IsoImageFilesystem *fs);
 
+/**
+ * Get the publisher identifier for an existent image. The returned string 
+ * belong to the IsoImageFilesystem and shouldn't be free() nor modified.
+ */
 const char *iso_image_fs_get_publisher_id(IsoImageFilesystem *fs);
 
+/**
+ * Get the data preparer identifier for an existent image. The returned string 
+ * belong to the IsoImageFilesystem and shouldn't be free() nor modified.
+ */
 const char *iso_image_fs_get_data_preparer_id(IsoImageFilesystem *fs);
 
+/**
+ * Get the system identifier for an existent image. The returned string belong
+ * to the IsoImageFilesystem and shouldn't be free() nor modified.
+ */
 const char *iso_image_fs_get_system_id(IsoImageFilesystem *fs);
 
+/**
+ * Get the application identifier for an existent image. The returned string 
+ * belong to the IsoImageFilesystem and shouldn't be free() nor modified.
+ */
 const char *iso_image_fs_get_application_id(IsoImageFilesystem *fs);
 
+/**
+ * Get the copyright file identifier for an existent image. The returned string
+ * belong to the IsoImageFilesystem and shouldn't be free() nor modified.
+ */
 const char *iso_image_fs_get_copyright_file_id(IsoImageFilesystem *fs);
 
+/**
+ * Get the abstract file identifier for an existent image. The returned string
+ * belong to the IsoImageFilesystem and shouldn't be free() nor modified.
+ */
 const char *iso_image_fs_get_abstract_file_id(IsoImageFilesystem *fs);
 
+/**
+ * Get the biblio file identifier for an existent image. The returned string 
+ * belong to the IsoImageFilesystem and shouldn't be free() nor modified.
+ */
 const char *iso_image_fs_get_biblio_file_id(IsoImageFilesystem *fs);
 
 #endif /*LIBISO_FS_IMAGE_H_*/
diff --git a/src/fs_local.c b/src/fs_local.c
index e2e066f..442bbe4 100644
--- a/src/fs_local.c
+++ b/src/fs_local.c
@@ -629,6 +629,7 @@ int iso_local_filesystem_new(IsoFilesystem **fs)
         }
 
         /* fill struct */
+        strncpy(lfs->type, "file", 4);
         lfs->refcount = 1;
         lfs->data = NULL; /* we don't need private data */
         lfs->get_root = lfs_get_root;
diff --git a/src/fsource.h b/src/fsource.h
index eb63fdf..af54377 100644
--- a/src/fsource.h
+++ b/src/fsource.h
@@ -26,6 +26,7 @@
 
 typedef struct Iso_File_Source IsoFileSource;
 typedef struct Iso_Filesystem IsoFilesystem;
+typedef struct IsoFileSource_Iface IsoFileSourceIface;
 
 /**
  * See IsoFilesystem->get_id() for info about this.
@@ -51,6 +52,12 @@ extern unsigned int iso_fs_global_id;
  */
 struct Iso_Filesystem
 {
+    /**
+     * Type of filesystem. 
+     * "file" -> local filesystem
+     * "iso " -> iso image filesystem
+     */
+    char type[4];
 
     /**
      * Get the root of a filesystem.
@@ -123,7 +130,7 @@ struct Iso_Filesystem
     void *data;
 };
 
-typedef struct IsoFileSource_Iface
+struct IsoFileSource_Iface
 {
 
     /**
@@ -306,7 +313,7 @@ typedef struct IsoFileSource_Iface
      * TODO #00004 Add a get_mime_type() function.
      * This can be useful for GUI apps, to choose the icon of the file
      */
-} IsoFileSourceIface;
+};
 
 struct Iso_File_Source
 {
@@ -492,7 +499,15 @@ int iso_file_source_readlink(IsoFileSource *src, char *buf, size_t bufsiz);
  */
 IsoFilesystem* iso_file_source_get_filesystem(IsoFileSource *src);
 
+/**
+ * Take a ref to the given IsoFilesystem
+ */
 void iso_filesystem_ref(IsoFilesystem *fs);
+
+/**
+ * Drop your ref to the given IsoFilesystem, evetually freeing associated 
+ * resources.
+ */
 void iso_filesystem_unref(IsoFilesystem *fs);
 
 /**
diff --git a/src/libisofs.h b/src/libisofs.h
index 65ac801..2580279 100644
--- a/src/libisofs.h
+++ b/src/libisofs.h
@@ -93,11 +93,13 @@ enum iso_replace_mode {
      */
 };
 
+typedef struct ecma119_write_opts Ecma119WriteOpts;
+
 /**
  * Holds the options for the image generation.
  */
-typedef struct
-{
+struct ecma119_write_opts {
+
     int level; /**< ISO level to write at. */
 
     /** Which extensions to support. */
@@ -252,9 +254,9 @@ typedef struct
      * buffer.
      */
     size_t fifo_size;
-} Ecma119WriteOpts;
+};
 
-typedef struct Iso_Data_Source IsoDataSource;
+typedef struct iso_data_source IsoDataSource;
 
 /**
  * Data source used by libisofs for reading an existing image.
@@ -268,7 +270,7 @@ typedef struct Iso_Data_Source IsoDataSource;
  * it with regular .iso images, and also with block devices that represent a 
  * drive.
  */
-struct Iso_Data_Source {
+struct iso_data_source {
     
     /** 
      * Reference count for the data source. Should be 1 when a new source
diff --git a/src/node.c b/src/node.c
index 139fc2a..ef02297 100644
--- a/src/node.c
+++ b/src/node.c
@@ -530,7 +530,7 @@ int iso_dir_iter_remove(IsoDirIter *iter)
 }
 
 /**
- * Get the destination of a node (in UTF-8).
+ * Get the destination of a node.
  * The returned string belongs to the node and should not be modified nor
  * freed. Use strdup if you really need your own copy.
  */