-;;;; The standard, non-SBCL-specific packages COMMON-LISP,
-;;;; COMMON-LISP-USER, and KEYWORD are also handled through other
-;;;; mechanisms.
+;;;; * the standard, non-SBCL-specific packages COMMON-LISP,
+;;;; COMMON-LISP-USER, and KEYWORD
+;;;;
+;;;; The packages are named SB!FOO here and elsewhere in
+;;;; cross-compilation, in order to avoid collision with corresponding
+;;;; SB-FOO packages in the cross-compilation host. They're renamed to
+;;;; SB-FOO later, after the danger of collision has passed.