HP 8753E Programming And Command Reference Manual page 71

Range The range of acceptable inputs and corresponding
units.
Symbol conventions:
Optional data.
D Numerical data.
I An integer appendage that is part of the command.
For example, CLEA<I>, where I= 1 to 5, indicates
that the actual commands are CLEAl, CLEAS,
A character string operand which must be enclosed by
double quotes.
A necessary appendage.
An either/or choice in appendages.
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