@c essay @sp 10
@c essay @comment The title is printed in a large font.
@c essay @title Data Representation in Guile
-@c essay @subtitle $Id: data-rep.texi,v 1.13 2003-06-21 23:02:58 kryde Exp $
+@c essay @subtitle $Id: data-rep.texi,v 1.14 2003-08-29 23:32:21 kryde Exp $
@c essay @subtitle For use with Guile @value{VERSION}
@c essay @author Jim Blandy
@c essay @author Free Software Foundation
Create a reference to the given object or objects, so they're certain
to be present on the stack or in a register and hence will not be
freed by the garbage collector before this point.
+
+Note that these functions can only be applied to ordinary C local
+variables (ie.@: ``automatics''). Objects held in global or static
+variables or some malloced block or the like cannot be protected with
+this mechanism.
@end deftypefn
For example, consider a procedure to convert image data to a list of