One of the keywords
An integer in the inclusive range [0,7], or
A function designator.
The arguments passed to func.
See also the keyword
:allocation to make-array, which catches the most common cases.
It is probably quite rare that it is useful to use this function, unless the function allocates a lot, and you are certain that every object that is allocated of the allocation type is long-lived, which is normally difficult to tell.
LispWorks User Guide and Reference Manual - 13 Feb 2015