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externals/mbedtls/SUPPORT.md

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+## Documentation
+
+Here are some useful sources of information about using Mbed TLS:
+
+- [ReadTheDocs](https://mbed-tls.readthedocs.io/);
+- API documentation, see the [Documentation section of the
+  README](README.md#documentation);
+- the `docs` directory in the source tree;
+- the [Mbed TLS Knowledge Base](https://mbed-tls.readthedocs.io/en/latest/kb/);
+- the [Mbed TLS mailing-list
+  archives](https://lists.trustedfirmware.org/archives/list/mbed-tls@lists.trustedfirmware.org/).
+
+## Asking Questions
+
+If you can't find your answer in the above sources, please use the [Mbed TLS
+mailing list](https://lists.trustedfirmware.org/mailman3/lists/mbed-tls.lists.trustedfirmware.org).