The CHRMAC program can be used to create character macros that can be
called by the sequence ESC n CR where n is a decimal number and CR is
carriage return.  This top-level system macro facility makes short macros
available for input to any program or the monitor itself.  The complete
documentation of the macro facility of the monitor is described in the
file MACROS.ME[UP,DOC].  The documentation for the CHRMAC program can be
gotten by running the program (R CHRMAC<cr>) and typing question-mark (?).
When defining a macro within CHRMAC, type <altmode>? for details on the
input forms used in such defining.

See also MONCOM.BH[S,DOC] (or section 5.1 of the Monitor Command Manual)
for details on the LOGIN option CHRMAC which makes LOGIN set up your
macros for you.