Document KNOWN LIMITATIONS

README.rst

@@ -219,6 +219,27 @@ several options:
 
 * Contact info@uplex.de to receive a commercial invoice for SWIFT payment.
 
+KNOWN LIMITATIONS
+=================
+
+If you are interested in supporting work to lift these known
+limitations, please consider supporting the project (see above).
+
+.. _#21: https://gitlab.com/uplex/varnish/slash/-/issues/21
+
+* The IO subsystem is configured at compile time and there is no
+  runtime fallback. For example, if io_uring is configured at compile
+  time, but not at runtime, SLASH/fellow will fail rather than falling
+  back to an alternative IO subsystem. (`#21`_)
+
+* SLASH/fellow data on persistent storage is stored in native byte
+  order, so storage can not be transported to systems with a different
+  byte order and loaded there.
+
+  Note that the disk layout is prepared to support endianness
+  conversion, so this limitation is also one which would "just" need a
+  sponsor to remove.
+
 PERFORMANCE
 ===========