@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2008-2021 Jonathan Schleifer <js@nil.im>
+ * Copyright (c) 2008-2022 Jonathan Schleifer <js@nil.im>
  *
  * All rights reserved.
  *
  * This file is part of ObjFW. It may be distributed under the terms of the
  * Q Public License 1.0, which can be found in the file LICENSE.QPL included in
@@ -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
@@ -118,10 +119,13 @@
 		     itemSize: (size_t)itemSize;
 
 /**
  * @brief Creates a new OFData with the specified `count` items of size 1 by
  *	  taking over ownership of the specified items pointer.
+ *
+ * If initialization fails for whatever reason, the passed memory is *not*
+ * free'd if `freeWhenDone` is true.
  *
  * @param items The items to store in the OFData
  * @param count The number of items
  * @param freeWhenDone Whether to free the pointer when it is no longer needed
  *		       by the OFData
@@ -132,10 +136,13 @@
 		       freeWhenDone: (bool)freeWhenDone;
 
 /**
  * @brief Creates a new OFData with the specified `count` items of the
  *	  specified size by taking ownership of the specified items pointer.
+ *
+ * If initialization fails for whatever reason, the passed memory is *not*
+ * free'd if `freeWhenDone` is true.
  *
  * @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
  * @param freeWhenDone Whether to free the pointer when it is no longer needed
@@ -167,13 +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;
 
 /**
@@ -184,21 +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
@@ -210,10 +217,13 @@
 
 /**
  * @brief Initializes an already allocated OFData with the specified `count`
  *	  items of size 1 by taking over ownership of the specified items
  *	  pointer.
+ *
+ * If initialization fails for whatever reason, the passed memory is *not*
+ * free'd if `freeWhenDone` is true.
  *
  * @param items The items to store in the OFData
  * @param count The number of items
  * @param freeWhenDone Whether to free the pointer when it is no longer needed
  *		       by the OFData
@@ -225,10 +235,13 @@
 
 /**
  * @brief Initializes an already allocated OFData with the specified `count`
  *	  items of the specified size by taking ownership of the specified
  *	  items pointer.
+ *
+ * If initialization fails for whatever reason, the passed memory is *not*
+ * free'd if `freeWhenDone` is true.
  *
  * @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
  * @param freeWhenDone Whether to free the pointer when it is no longer needed
@@ -260,13 +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;
 
 /**