/sys$common/syshlp/helplib.hlb RECALL, Parameter  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 command-specifier

    Specifies the number or the first several characters of the
    command you want to recall. You cannot use any of the qualifiers
    in conjunction with a command-specifier.

    The specified characters should be unique. If they are not
    unique, the RECALL command displays the most recently entered
    command line that matches those characters. For example, suppose
    you enter a SHOW STATUS command and later enter a SHOW TIME
    command. If you then type RECALL S, the SHOW TIME command is
    recalled. You must type RECALL SHOW S to recall the SHOW STATUS
    command. The number of the command can be from 1 to 254 (where 1
    is the last command entered).

    The RECALL command itself is never assigned a number. If no
    command specifier is entered, the RECALL command recalls the most
    recently entered command. You can use the /ALL qualifier to have
    the system display all the commands in the recall buffer, along
    with their command numbers, to verify the number of the command
    you want to recall.