diff --git a/include/mode-private.h b/include/mode-private.h
index 633065f0..e047bee8 100644
--- a/include/mode-private.h
+++ b/include/mode-private.h
@@ -2,6 +2,8 @@
 #define ROFI_MODE_PRIVATE_H
 
 #include <gmodule.h>
+
+/** ABI version to check if loaded plugin is compatible. */
 #define ABI_VERSION    0x00000004
 
 /**
diff --git a/include/x11-helper.h b/include/x11-helper.h
index ed63b2d8..98cd8ccd 100644
--- a/include/x11-helper.h
+++ b/include/x11-helper.h
@@ -262,6 +262,9 @@ int x11_modifier_active ( unsigned int mask, int key );
  */
 void x11_disable_decoration ( xcb_window_t window );
 
+/**
+ * List of window managers that need different behaviour to functioning.
+ */
 typedef enum
 {
     /** Default EWHM compatible window manager */
diff --git a/source/helper.c b/source/helper.c
index 7a5e5cac..ff1d002c 100644
--- a/source/helper.c
+++ b/source/helper.c
@@ -53,6 +53,9 @@
 
 #define LOG_DOMAIN    "Helper"
 
+/**
+ * Textual description of positioning rofi.
+ */
 const char *const monitor_position_entries[] = {
     "on focused monitor",
     "on focused window",
diff --git a/source/rofi.c b/source/rofi.c
index baada8c0..7540dd9a 100644
--- a/source/rofi.c
+++ b/source/rofi.c
@@ -403,8 +403,9 @@ static void cleanup ()
 /**
  * Collected modi
  */
-// List of (possibly uninitialized) modi's
+/**  List of (possibly uninitialized) modi's */
 Mode         ** available_modi  = NULL;
+/** Length of #num_available_modi */
 unsigned int num_available_modi = 0;
 
 /**
diff --git a/source/widgets/textbox.c b/source/widgets/textbox.c
index cb30e624..7e3648ca 100644
--- a/source/widgets/textbox.c
+++ b/source/widgets/textbox.c
@@ -68,6 +68,7 @@ typedef struct TBFontConfig
     PangoFontMetrics     *metrics;
 }TBFontConfig;
 
+/** HashMap of previously parsed font descriptions. */
 static GHashTable *tbfc_cache = NULL;
 
 static gboolean textbox_blink ( gpointer data )
@@ -709,6 +710,8 @@ void textbox_setup ( void )
 {
     tbfc_cache = g_hash_table_new_full ( g_str_hash, g_str_equal, NULL, (GDestroyNotify) tbfc_entry_free );
 }
+
+/** Name of the default font (if none is given) */
 const char *default_font_name = "default";
 void textbox_set_pango_context ( const char *font, PangoContext *p )
 {