Final answer:
In the context of P&ID revisions, changes are typically noted with the issue number inside a triangle, which is the standard symbol used to indicate modifications. Electronic versions may use hyperlinked red squares that lead to a detailed changes section.
Step-by-step explanation:
Changes on a new issue of a P&ID (Piping and Instrumentation Diagram) may be noted with the issue number inside a triangle. In the context of P&ID revisions, triangles serve as the standard symbol to indicate that a modification has been made. This triangle notation helps viewers quickly identify changes from the previous version. It is also common practice to include a revision history table somewhere on the document, which lists all the issue numbers along with a description of the changes and the date.
Electronic versions of P&IDs often enhance the change identification process. For example, a red square in the text may be hyperlinked to a detailed entry in a Changes and Corrections section, with the entry also providing a hyperlinked page reference for easy navigation. This system ensures that anyone reviewing the diagram can efficiently find and understand all the modifications made since the original release.