- * @param int|string $key The cache key to use for retrieval later
- * @param mixed $data The data to add to the cache store
- * @param string $group The group to add the cache to
- * @param int $expire When the cache data should be expired
- * @return bool False if cache key and group already exist, true on success
+ * @see WP_Object_Cache::add()
+ * @global WP_Object_Cache $wp_object_cache Object cache global instance.
+ *
+ * @param int|string $key The cache key to use for retrieval later.
+ * @param mixed $data The data to add to the cache.
+ * @param string $group Optional. The group to add the cache to. Enables the same key
+ * to be used across groups. Default empty.
+ * @param int $expire Optional. When the cache data should expire, in seconds.
+ * Default 0 (no expiration).
+ * @return bool False if cache key and group already exist, true on success.