Index: src/OFData.h
==================================================================
--- src/OFData.h
+++ src/OFData.h
@@ -43,15 +43,15 @@
  * for OFData with item size 1.
  */
 @interface OFData: OFObject <OFCopying, OFMutableCopying, OFComparing,
     OFSerialization, OFMessagePackRepresentation>
 {
-	unsigned char *_items;
+	unsigned char *_Nullable _items;
 	size_t _count, _itemSize;
 	bool _freeWhenDone;
 @private
-	OFData *_parentData;
+	OFData *_Nullable _parentData;
 	OF_RESERVE_IVARS(OFData, 4)
 }
 
 /**
  * @brief The size of a single item in the OFData in bytes.
@@ -66,11 +66,12 @@
 /**
  * @brief All elements of the OFData as a C array.
  *
  * @warning The pointer is only valid until the OFData is changed!
  */
-@property (readonly, nonatomic) const void *items OF_RETURNS_INNER_POINTER;
+@property OF_NULLABLE_PROPERTY (readonly, nonatomic) const void *items
+    OF_RETURNS_INNER_POINTER;
 
 /**
  * @brief The first item of the OFData or `NULL`.
  */
 @property OF_NULLABLE_PROPERTY (readonly, nonatomic) const void *firstItem
@@ -173,13 +174,13 @@
  */
 + (instancetype)dataWithContentsOfURL: (OFURL *)URL;
 
 /**
  * @brief Creates a new OFData with an item size of 1, containing the data of
- *	  the string representation.
+ *	  the hex string representation.
  *
- * @param string The string representation of the data
+ * @param string The hex string representation of the data
  * @return A new autoreleased OFData
  */
 + (instancetype)dataWithStringRepresentation: (OFString *)string;
 
 /**
@@ -190,21 +191,21 @@
  * @return A new autoreleased OFData
  */
 + (instancetype)dataWithBase64EncodedString: (OFString *)string;
 
 /**
- * @brief Initialized an already allocated OFData with the specified `count`
+ * @brief Initializes an already allocated OFData with the specified `count`
  *	  items of size 1.
  *
  * @param items The items to store in the OFData
  * @param count The number of items
  * @return An initialized OFData
  */
 - (instancetype)initWithItems: (const void *)items count: (size_t)count;
 
 /**
- * @brief Initialized an already allocated OFData with the specified `count`
+ * @brief Initializes an already allocated OFData with the specified `count`
  *	  items of the specified size.
  *
  * @param items The items to store in the OFData
  * @param count The number of items
  * @param itemSize The item size of a single item in bytes
@@ -272,13 +273,13 @@
  */
 - (instancetype)initWithContentsOfURL: (OFURL *)URL;
 
 /**
  * @brief Initializes an already allocated OFData with an item size of 1,
- *	  containing the data of the string representation.
+ *	  containing the data of the hex string representation.
  *
- * @param string The string representation of the data
+ * @param string The hex string representation of the data
  * @return A new autoreleased OFData
  */
 - (instancetype)initWithStringRepresentation: (OFString *)string;
 
 /**

Index: src/OFMutableData.h
==================================================================
--- src/OFMutableData.h
+++ src/OFMutableData.h
@@ -37,11 +37,12 @@
  * @warning The pointer is only valid until the OFMutableData is changed!
  *
  * Modifying the returned array directly is allowed and will change the contents
  * of the data.
  */
-@property (readonly, nonatomic) void *mutableItems OF_RETURNS_INNER_POINTER;
+@property OF_NULLABLE_PROPERTY (readonly, nonatomic) void *mutableItems
+    OF_RETURNS_INNER_POINTER;
 
 /**
  * @brief The first item of the OFMutableData or `NULL`.
  */
 @property OF_NULLABLE_PROPERTY (readonly, nonatomic) void *mutableFirstItem