+/*!
+@brief
+ Returns the extra name of libbabeltrace2's version.
+
+The extra name of the library's version can be set at build time for a
+custom build.
+
+@returns
+ Library's version extra name, or \c NULL if not available.
+*/
+extern const char *bt_version_get_extra_name(void);
+
+/*!
+@brief
+ Returns the extra description of libbabeltrace2's version.
+
+The extra description of the library's version can be set at build time
+for a custom build.
+
+@returns
+ @parblock
+ Library's version extra description, or \c NULL if not available.
+
+ Can contain newlines.
+ @endparblock
+*/
+extern const char *bt_version_get_extra_description(void);
+
+/*!
+@brief
+ Returns the extra patch names of libbabeltrace2's version.
+
+The extra patch names of the library's version can be set at build time
+for a custom build.
+
+@returns
+ @parblock
+ Library's version extra patch names, or \c NULL if not available.
+
+ Each line of the returned string contains the name of a patch
+ applied to Babeltrace's source tree for a custom build.
+ @endparblock
+*/
+extern const char *bt_version_get_extra_patch_names(void);
+