Added a few more comments. Changed rt_hash to return an enum record_type rather than an enum record_type_hash. Modified rfs and rfs_refr to suit.

espReader/ESPTree.h

@@ -10,11 +10,32 @@
 typedef struct meta_node MetaNode;
 
 /* Meta Nodes are used for constructing a more flexible tree structure 
- * on top of 
+ * on top of the natural structure of ESP/ESM files.
+ * 
+ * Meta Nodes do not create a pure tree structure, rather they have pointers to
+ * their parent and first child, and children have pointers backwards and 
+ * forward through a linked list of all of the children of the parent node.
+ * 
+ * There is no root node as such, rather there is a root linked list for which
+ * all of the Meta Nodes have no parents.
+ * 
+ * While the ESP/ESM buffer can be modified in-place, any modification that
+ * changes the size of the stored data cannot be directly written to the buffer
+ * without first shifting all of the data after the point of modification. 
+ * 
+ * Modifications that change data size are:
+ * - Adding or deleting a group or record
+ * - Adding or deleting a field in a record
+ * - Changing a variable length field with data of different length
+ * 
+ * With a Meta Node you can instead allocate new, arbitrarily sized memory for 
+ * the node data. The Meta Node tree can then be walked to reconstruct a
+ * contiguous view of discontiguous memory.
  */
 struct meta_node {
     Node n;
     MetaNode *parent;
+    MetaNode *child;
     MetaNode *prev;
     MetaNode *next;
 };