Library /sys$common/syshlp/sysmanhelp.hlb IO, CONNECT, Qualifiers, /LOG  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /LOG=(ALL,CRB,DDB,DPT,IDB,SB,UCB)
    /NOLOG (default)

    Controls whether SYSMAN displays the addresses of the specified
    control blocks. The default value for the /LOG qualifier is
    /LOG=ALL. If /LOG=UCB is specified, a message similar to the
    following one is displayed:

    %SYSMAN-I-IOADDRESS, the UCB is located at address 805AB000