Library /sys$common/syshlp/pca$help.hlb SET, LOG, Description  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    The SET LOG command records all PCA input and output in the
    specified log file. Input is recorded as entered. Output is
    recorded with a leading exclamation point (!). Since the
    exclamation point is the PCA comment character, you can rerun the
    logged PCA session by using the log file as a command procedure.