diff --git a/llvm/docs/BitCodeFormat.rst b/llvm/docs/BitCodeFormat.rst
--- a/llvm/docs/BitCodeFormat.rst
+++ b/llvm/docs/BitCodeFormat.rst
@@ -1355,6 +1355,8 @@
 * `CONSTANTS_BLOCK`_
 * `VALUE_SYMTAB_BLOCK`_
 * `METADATA_ATTACHMENT`_
+* `METADATA_BLOCK`_
+* `USELIST_BLOCK`_
 
 .. _VALUE_SYMTAB_BLOCK:
 
@@ -1393,3 +1395,29 @@
 not succeeded by another intervening ``STRTAB`` block. Normally a bitcode
 file will have a single string table, but it may have more than one if it
 was created by binary concatenation of multiple bitcode files.
+
+.. _USELIST_BLOCK:
+
+USELIST_BLOCK Contents
+----------------------
+
+The ``USELIST_BLOCK`` block (id 18) contains records mapping LLVM values to
+their users.
+
+.. _USELIST_CODE_DEFAULT:
+
+USELIST_CODE_DEFAULT
+^^^^^^^^^^^^^^^^^^^^
+
+``[DEFAULT, index..., value-id]``
+
+The ``DEFAULT`` record (code 1) ...
+
+.. _USELIST_CODE_BB:
+
+USELIST_CODE_BB
+^^^^^^^^^^^^^^^
+
+``[BB, index..., bb-id]``
+
+The ``BB`` record (code 2) ...