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+## Removal of deprecated functions
+
+### Removal of deprecated X.509 functions
+
+The deprecated function `mbedtls_x509write_crt_set_serial()` has been removed. The function was superseded by `mbedtls_x509write_crt_set_serial_raw()`.
+
+### Removal of deprecated SSL functions
+
+The deprecated function `mbedtls_ssl_conf_curves()` has been removed.
+The function was superseded by `mbedtls_ssl_conf_groups()`.
+
+### Removal of `compat-2.x.h`
+
+The header `compat-2.x.h`, containing some definitions for backward compatibility with Mbed TLS 2.x, has been removed.