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+# Registry Reading, etc
+
+This provides tools for dealing with the legacy binary types database
+format, still in use by extensions and the core code. While the actual
+binary file format is implemented by the `store` code, the wrapper
+that turns this into a type registry is implemented here.
+
+While this code is primarily used in only two modes:
+
+* linear write / concatenate
+* random access read
+
+The API unfortunately exposes a random-access write approach, which -
+while ~unused needs before we can re-write this away from the store
+backend.