+Enabling versioning macros
+__________________________
+
+Finally, we need to indicate to the :doc:`meson/ninja build system
+<../prog_guide/build-sdk-meson>` to enable versioning macros when building the
+library or driver. In the libraries or driver where we have added symbol
+versioning, in the ``meson.build`` file we add the following
+
+.. code-block:: none
+
+ use_function_versioning = true
+
+at the start of the head of the file. This will indicate to the tool-chain to
+enable the function version macros when building. There is no corresponding
+directive required for the ``make`` build system.
+
+
+.. _aliasing_experimental_symbols:
+
+Aliasing experimental symbols
+_____________________________
+
+In situations in which an ``experimental`` symbol has been stable for some time,
+and it becomes a candidate for promotion to the stable ABI. At this time, when
+promoting the symbol, the maintainer may choose to provide an alias to the
+``experimental`` symbol version, so as not to break consuming applications.
+This alias is then dropped in the next major ABI version.
+
+The process to provide an alias to ``experimental`` is similar to that, of
+:ref:`symbol versioning <example_abi_macro_usage>` described above.
+Assume we have an experimental function ``rte_acl_create`` as follows:
+
+.. code-block:: c
+
+ #include <rte_compat.h>
+
+ /*
+ * Create an acl context object for apps to
+ * manipulate
+ */
+ __rte_experimental
+ struct rte_acl_ctx *
+ rte_acl_create(const struct rte_acl_param *param)
+ {
+ ...
+ }
+
+In the map file, experimental symbols are listed as part of the ``EXPERIMENTAL``
+version node.
+
+.. code-block:: none
+
+ DPDK_21 {
+ global:
+ ...
+
+ local: *;
+ };
+
+ EXPERIMENTAL {
+ global:
+
+ rte_acl_create;
+ };
+
+When we promote the symbol to the stable ABI, we simply strip the
+``__rte_experimental`` annotation from the function and move the symbol from the
+``EXPERIMENTAL`` node, to the node of the next major ABI version as follow.
+
+.. code-block:: c
+
+ /*
+ * Create an acl context object for apps to
+ * manipulate
+ */
+ struct rte_acl_ctx *
+ rte_acl_create(const struct rte_acl_param *param)
+ {
+ ...
+ }
+
+We then update the map file, adding the symbol ``rte_acl_create``
+to the ``DPDK_22`` version node.
+
+.. code-block:: none
+
+ DPDK_21 {
+ global:
+ ...
+
+ local: *;
+ };
+
+ DPDK_22 {
+ global:
+
+ rte_acl_create;
+ } DPDK_21;
+
+
+Although there are strictly no guarantees or commitments associated with
+:ref:`experimental symbols <experimental_apis>`, a maintainer may wish to offer
+an alias to experimental. The process to add an alias to experimental,
+is similar to the symbol versioning process. Assuming we have an experimental
+symbol as before, we now add the symbol to both the ``EXPERIMENTAL``
+and ``DPDK_22`` version nodes.
+
+.. code-block:: c
+
+ #include <rte_compat.h>;
+ #include <rte_function_versioning.h>
+
+ /*
+ * Create an acl context object for apps to
+ * manipulate
+ */
+ struct rte_acl_ctx *
+ rte_acl_create(const struct rte_acl_param *param)
+ {
+ ...
+ }
+
+ __rte_experimental
+ struct rte_acl_ctx *
+ rte_acl_create_e(const struct rte_acl_param *param)
+ {
+ return rte_acl_create(param);
+ }
+ VERSION_SYMBOL_EXPERIMENTAL(rte_acl_create, _e);
+
+ struct rte_acl_ctx *
+ rte_acl_create_v22(const struct rte_acl_param *param)
+ {
+ return rte_acl_create(param);
+ }
+ BIND_DEFAULT_SYMBOL(rte_acl_create, _v22, 22);
+
+In the map file, we map the symbol to both the ``EXPERIMENTAL``
+and ``DPDK_22`` version nodes.
+
+.. code-block:: none
+
+ DPDK_21 {
+ global:
+ ...
+
+ local: *;
+ };
+
+ DPDK_22 {
+ global:
+
+ rte_acl_create;
+ } DPDK_21;
+
+ EXPERIMENTAL {
+ global:
+
+ rte_acl_create;
+ };
+
+.. note::
+
+ Please note, similar to :ref:`symbol versioning <example_abi_macro_usage>`,
+ when aliasing to experimental you will also need to take care of
+ :ref:`mapping static symbols <mapping_static_symbols>`.
+
+
+.. _abi_deprecation: