感谢你补上试译文！
承包商专案经理与采购方指定工区代表将一同条列超出原合约范围所增减的服务和成本。
该条列清单于必要时更新，并将载明项目描述、施工方为何、施工估价，以及由“采购
方”、“承包商”或“另订”支付成本。
※ 引述《cellline (PiPi)》之铭言：
卖方之专案经理与买方特定工区代表人创设附加服务增减项目或发生在原契约范围之外衍
生之成本费用。该项目清单基础将依据“按规定要求”进行项目更新并包含特定项目叙述
，该方将做这项工作，估计成本的工作，并命名为“买方”，承包商“，或”被确定“作
为负责所产生的费用。
以上是我初步翻译结果，但我不确定是否语意偏差，再惠请大家协助订正语句，谢谢。
※ 引述《cellline (PiPi)》之铭言：
: The Contractor’s Project Manager and the Purchaser’s designated Job Site
: Representative will create a plus/minus list of additional services or cost
: occurred that are outside of the scope of the original contract. The list
: will be updated on an “as required” basis and will include a description of
: the particular item, the party that will do the work, an estimated cost of
: the work, and name the “Purchaser”, the Contractor”, or “to be determined
: ” as the party responsible for the costs incurred.