accessional

adj.of or constituting an accession

1. The museum provided accessional documentation for every new item added to the collection.
   博物馆为每一件新添加到藏品中的物品提供了附加文件。
2. The accessional rights of the new member were clearly outlined in the agreement.
   新成员的加入权利在协议中得到了明确说明。