diff --git a/doc/asdf.texinfo b/doc/asdf.texinfo
index a26dfa8f2e85e276f92aec11698a611d0901b81e..9d62311227c80bb35774ce541eec939df5e3451e 100644
--- a/doc/asdf.texinfo
+++ b/doc/asdf.texinfo
@@ -2388,13 +2388,17 @@ the file's @code{last-modified} time exceeds the @code{last-modified} time
 of the system in memory
 @end itemize
 
+@cindex ASDF-USER package
 When system definitions are loaded from @file{.asd} files,
-a new scratch package is created for them to load into,
-so that different systems do not overwrite each others operations.
-The user may also wish to (and is recommended to)
+they are implicitly loaded into the @code{ASDF-USER} package, which uses
+@code{ASDF}.
+The programmer is also recommended to
 include @code{defpackage} and @code{in-package} forms
-in his system definition files, however,
-so that they can be loaded manually if need be.
+in his system definition files, however, so that they 
+will behave identically if loaded manually for development or debugging.
+One should define one's own package (typically using @code{ASDF} and
+@code{COMMON-LISP}) if adding new classes, methods, etc., in order that
+different systems do not overwrite each others' extensions.
 
 The default value of @code{*system-definition-search-functions*}
 is a list of two functions.
@@ -2409,6 +2413,25 @@ Hence, it is strongly advised to define a system
 @var{foo} in the corresponding file @var{foo.asd}.
 @end defun
 
+@defun locate-system name
+
+This function should typically @emph{not} be invoked directly.  It is
+exported as part of the API only for programmers who wish to provide
+their own @code{*system-definition-search-functions*}.
+
+Given a system @var{name} designator, try to locate where to load the system from.
+Returns five values: @var{foundp}, @var{found-system}, @var{pathname},
+@var{previous}, and @var{previous-time}.
+@var{foundp} is true when a system was found,
+either a new as yet unregistered one, or a previously registered one.
+@var{found-system} when not null is a @code{system} object that may be @code{register-system}'ed.
+@var{pathname} when not null is a path from which to load the system,
+either associated with @var{found-system}, or with the @var{previous} system.
+@var{previous} when not null is a previously loaded @code{system} object
+of the same name.
+@var{previous-time} when not null is the time at which the @var{previous} system was loaded.
+@end defun
+
 @defun find-component base path
 
 Given a @var{base} component (or designator for such),
diff --git a/find-system.lisp b/find-system.lisp
index fde016c3dc59793d97ab4b57cc639eb68b40b768..b85c4f911982cf44153988affcc5a93017151d77 100644
--- a/find-system.lisp
+++ b/find-system.lisp
@@ -99,8 +99,8 @@ of which is a system object.")
   (defun clear-defined-systems ()
     ;; Invalidate all systems but ASDF itself, if registered.
     (loop :for name :being :the :hash-keys :of *defined-systems*
-	  :unless (equal name "asdf")
-	    :do (clear-defined-system name)))
+          :unless (equal name "asdf")
+            :do (clear-defined-system name)))
 
   (register-hook-function '*post-upgrade-cleanup-hook* 'clear-defined-systems nil)
 
@@ -353,8 +353,8 @@ but not loaded in memory"
 Returns five values: FOUNDP FOUND-SYSTEM PATHNAME PREVIOUS PREVIOUS-TIME
 FOUNDP is true when a system was found,
 either a new unregistered one or a previously registered one.
-FOUND-SYSTEM when not null is a SYSTEM object that may be REGISTER-SYSTEM'ed as is
-PATHNAME when not null is a path from where to load the system,
+FOUND-SYSTEM when not null is a SYSTEM object that may be REGISTER-SYSTEM'ed.
+PATHNAME when not null is a path from which to load the system,
 either associated with FOUND-SYSTEM, or with the PREVIOUS system.
 PREVIOUS when not null is a previously loaded SYSTEM object of same name.
 PREVIOUS-TIME when not null is the time at which the PREVIOUS system was loaded."
@@ -426,6 +426,6 @@ PREVIOUS-TIME when not null is the time at which the PREVIOUS system was loaded.
           (reinitialize-source-registry-and-retry ()
             :report (lambda (s)
                       (format s (compatfmt "~@<Retry finding system ~A after reinitializing the source-registry.~@:>") name))
-	    (unset-asdf-cache-entry `(locate-system ,name))
+            (unset-asdf-cache-entry `(locate-system ,name))
             (initialize-source-registry)))))))