diff --git a/BDF.markdown b/BDF.md
similarity index 58%
rename from BDF.markdown
rename to BDF.md
index 4ca5c55..ad63c72 100644
--- a/BDF.markdown
+++ b/BDF.md
@@ -4,14 +4,14 @@ The first four bits of each object give the type. Depending on the type, the nex
 
 * **0: Null** - Next four bits are zero.
 * **1: Boolean** - Next four bits give the value, which is 0 or 1.
-* **2: Integer** - Next four bits give the length, which is 0, 1, 2, 4 or 8. The value is an integer with the specified length.
-* **3: Float** - Next four bits give the length, which is 4 or 8. The value is a floating point number with the specified length.
-* **4: String** - Next four bits give the length-of-length, which is 0, 1, 2, 4 or 8. The length is an integer with the specified length-of-length. The value is a string with the specified length.
-* **5: Raw** - Next four bits give the length-of-length, which is 0, 1, 2, 4 or 8. The length is an integer with the specified length-of-length. The value is raw data with the specified length.
+* **2: Integer** - Next four bits give the length, which is 1, 2, 4 or 8. The value is an integer with the specified length.
+* **3: Float** - Next four bits give the length, which is 8. The value is a floating point number with the specified length.
+* **4: String** - Next four bits give the length-of-length, which is 1, 2, 4 or 8. The length is an integer with the specified length-of-length. The value is a string with the specified length.
+* **5: Raw** - Next four bits give the length-of-length, which is 1, 2, 4 or 8. The length is an integer with the specified length-of-length. The value is raw data with the specified length.
 * **6: List** - Next four bits are zero. The list contains zero or more elements followed by an end object. Elements may be of any type except end.
-* **7: Dictionary** - Next four bits are zero. The dictionary contains zero or more key-value pairs followed by an end object. Keys are strings, values may be of any type except end. Duplicate keys are not allowed.
+* **7: Dictionary** - Next four bits are zero. The dictionary contains zero or more key-value pairs followed by an end object. Keys are strings, values may be of any type except end.
 * **8: End** - Next four bits are zero. Marks the end of a list or dictionary.
 
 Integers and lengths are big-endian two's complement, floating point numbers are IEEE 754, and strings are UTF-8.
 
-Integers and lengths must be represented using the minimum number of bytes. If data containing a dictionary is being hashed or signed, the dictionary keys should be sorted in lexicographic order.
+If data is to be hashed or signed, integers and lengths should be represented using the minimum number of bytes, and dictionary keys should be unique and sorted in lexicographic order.