STACK

$X_1\ ...\ X_I\ I\ --\ X_1\ ...\ X_I\ X_1\ ...\ X_I$ $A_1\ A_2\ --\ A$ $D_1\ D_2\ --\ D$ $S_1\ S_2\ --\ S$

DESCRIPTION

Copies in the first form duplicates of the top I stack objects onto the stack.
In the other forms, copy copies all the elements of the first composite object into the second. The composite object operands must be of the same type. This form of copy copies the value of a composite object. This is quite different from dup and other operators that copy only the objects themselves. However, copy performs only one level of copying. It does not apply recursively to elements that are themselves composite objects; instead, the values of those elements become shared.

ORIGIN

Core code registered in systemdict.