diff --git a/contrib/lisp/ox-koma-letter.el b/contrib/lisp/ox-koma-letter.el
index d82c12553..f1ccc46a8 100644
--- a/contrib/lisp/ox-koma-letter.el
+++ b/contrib/lisp/ox-koma-letter.el
@@ -439,7 +439,8 @@ e.g. \"title-subject:t\"."
     (:inbuffer-with-backaddress nil "backaddress" 'koma-letter:empty)
     (:inbuffer-with-email nil "email" 'koma-letter:empty)
     (:inbuffer-with-foldmarks nil "foldmarks" 'koma-letter:empty)
-    (:inbuffer-with-phone nil "phone" 'koma-letter:empty))
+    (:inbuffer-with-phone nil "phone" 'koma-letter:empty)
+    (:inbuffer-with-place nil "place" 'koma-letter:empty))
   :translate-alist '((export-block . org-koma-letter-export-block)
 		     (export-snippet . org-koma-letter-export-snippet)
 		     (headline . org-koma-letter-headline)
@@ -745,9 +746,13 @@ a communication channel."
           (format "\\KOMAoption{backaddress}{%s}\n"
                   (if (plist-get info :with-backaddress) "true" "false")))
      ;; Place.
-     (and (funcall check-scope 'place)
-          (format "\\setkomavar{place}{%s}\n"
-                  (if (plist-get info :with-place) (plist-get info :place) "")))
+     (let ((with-place-set (funcall check-scope 'with-place))
+	   (place-set (funcall check-scope 'place)))
+       (and (or (and with-place-set place-set)
+		(and (eq scope 'buffer) (or with-place-set place-set)))
+	    (format "\\setkomavar{place}{%s}\n"
+		    (if (plist-get info :with-place) (plist-get info :place)
+		      ""))))
      ;; Folding marks.
      (and (funcall check-scope 'with-foldmarks)
           (let ((foldmarks (plist-get info :with-foldmarks)))
diff --git a/doc/org.texi b/doc/org.texi
index ed808bece..ac7d3a4e5 100644
--- a/doc/org.texi
+++ b/doc/org.texi
@@ -8620,9 +8620,10 @@ selected.
 @vindex org-agenda-category-filter-preset
 
 Filter the current agenda view with respect to the category of the item at
-point.  Pressing @code{<} another time will remove this filter.  You can add
-a filter preset through the option @code{org-agenda-category-filter-preset}
-(see below.)
+point.  Pressing @code{<} another time will remove this filter.  When called
+with a prefix argument exclude the category of the item at point from the
+agenda.  You can add a filter preset through the option
+@code{org-agenda-category-filter-preset} (see below.)
 
 @orgcmd{^,org-agenda-filter-by-top-headline}
 Filter the current agenda view and only display the siblings and the parent
diff --git a/lisp/org-agenda.el b/lisp/org-agenda.el
index a8661a775..9f85cfa98 100644
--- a/lisp/org-agenda.el
+++ b/lisp/org-agenda.el
@@ -7352,8 +7352,11 @@ in the agenda."
 (defvar org-agenda-filtered-by-category nil)
 
 (defun org-agenda-filter-by-category (strip)
-  "Keep only those lines in the agenda buffer that have a specific category.
-The category is that of the current line."
+  "Filter lines in the agenda buffer that have a specific category.
+The category is that of the current line.
+Without prefix argument, keep only the lines of that category.
+With a prefix argument, exclude the lines of that category.
+"
   (interactive "P")
   (if (and org-agenda-filtered-by-category
 	   org-agenda-category-filter)
@@ -7363,7 +7366,7 @@ The category is that of the current line."
        ((and cat strip)
         (org-agenda-filter-apply
          (push (concat "-" cat) org-agenda-category-filter) 'category))
-       ((and cat)
+       (cat
         (org-agenda-filter-apply
          (setq org-agenda-category-filter
 	       (list (concat "+" cat))) 'category))