AllOrder第一部分：总则与基本分类（表2-42的基础）Table 2-42 defines the ordering requirements for PCI Express Transactions. The rules defined in this section apply uniformly to all types of Transactions on PCI Express including Memory, I/O, Configuration, and Messages, except for Flow-Through IDE Streams which have modified ordering requirements (see § Section 6.33.4).翻译：表2-42定义了PCIe事务的排序要求。