diff --git a/doc/Default_configuration.md b/doc/Default_configuration.md
index 27e33d1..dd20823 100644
--- a/doc/Default_configuration.md
+++ b/doc/Default_configuration.md
@@ -275,32 +275,32 @@ view, not floating (i. e. tiled), the window title bar is not visible, the
 title is not hidden on the bug.n status bar and no window action is taken, when
 the window first is created.
 
-`Config_rule_#2=.*;.*;Window_isChild;1;0;0;1;1;0;`
-> Child windows (style WS_CHILD) will not be managed, are floating and the
-titles are hidden.
-
-`Config_rule_#3=.*;.*;Window_isPopup;0;0;0;1;1;0;`
-> Pop-up windows (style WS_POPUP) will not be managed, are floating and the
-titles are hidden.
-
-`Config_rule_#4=.*;.*;Window_isElevated;0;0;0;1;1;0;`
+`Config_rule_#2=.*;.*;Window_isElevated;0;0;0;1;1;0;`
 > Windows created by applications run as administrator cannot be managed by
 bug.n and are therefor excluded. If a higher numbered rule also covers elevated
-windows, it would precede rule #4 and therefor needs to be followed by an
+windows, it would precede rule #2 and therefor needs to be followed by an
 additional rule, which again would exclude those windows identified by the
 rule, but which are elevated.
 
+`Config_rule_#3=.*;.*;Window_isNotVisible;0;0;0;1;1;0;`
+> Windows, which are not visible (i. a. do not have the style WS_VISIBLE), will
+not be managed, are floating and have a title bar.
+
+`Config_rule_#4=.*;.*;Window_isPopup;0;0;0;1;1;0;`
+> Pop-up windows (style WS_POPUP) will not be managed, are floating and have a
+title bar.
+
 `Config_rule_#5=QWidget;.*;;1;0;0;0;0;0;`
 > Windows created by QT (QWidget) have the style WS_POPUP, but should be
-excluded from the preceding rule.
+excluded from rule #4.
 
 `Config_rule_#6=SWT_Window0;.*;;1;0;0;0;0;0;`
-> Also windows created by Java (SWT) e. g. Eclipse should be excluded from the
-second rule for the same reason as above.
+> Also windows created by Java (SWT) e. g. Eclipse should be excluded from rule
+ #4 for the same reason as above.
 
 `Config_rule_#7=Xming;.*;;1;0;0;0;0;0;`
-> Also Xming windows should be excluded from the second rule for the same
-reason as above.
+> Also Xming windows should be excluded from rule #4 for the same reason as
+above.
 
 `Config_rule_#8=CabinetWClass;.*;;1;0;0;0;1;0;`
 > Windows Explorer. If the window's title bar is hidden, it looks distorted.
@@ -312,7 +312,7 @@ windows.
 `Config_rule_#10=Chrome_WidgetWin_1;.*;;1;0;0;0;1;0;`
 > Chrome web browser. If the window's title bar is hidden, it looks distorted.
 
-`Config_rule_#11=Chrome_WidgetWin_1;.*;Window_isPopup;1;0;0;1;1;0;`
+`Config_rule_#11=Chrome_WidgetWin_1;.*;Window_isPopup;0;0;0;1;1;0;`
 > With the preceding rule overriding #2 Chrome pop-up windows would be treated
 as new main windows.
 
diff --git a/src/Config.ahk b/src/Config.ahk
index 386fb5b..3a9c5e0 100644
--- a/src/Config.ahk
+++ b/src/Config.ahk
@@ -80,16 +80,16 @@ Config_init() {
 
   ;; Config_rule_#<i> := "<class>;<title>;<function name>;<is managed>;<m>;<tags>;<is floating>;<is decorated>;<hide title>;<action>"
   Config_rule_#1   := ".*;.*;;1;0;0;0;0;0;"
-  Config_rule_#2   := ".*;.*;Window_isChild;1;0;0;1;1;0;"
-  Config_rule_#3   := ".*;.*;Window_isPopup;0;0;0;1;1;0;"
-  Config_rule_#4   := ".*;.*;Window_isElevated;0;0;0;1;1;0;"
+  Config_rule_#2   := ".*;.*;Window_isElevated;0;0;0;1;1;0;"
+  Config_rule_#3   := ".*;.*;Window_isNotVisible;0;0;0;1;1;0;"
+  Config_rule_#4   := ".*;.*;Window_isPopup;0;0;0;1;1;0;"
   Config_rule_#5   := "QWidget;.*;;1;0;0;0;0;0;"
   Config_rule_#6   := "SWT_Window0;.*;;1;0;0;0;0;0;"
   Config_rule_#7   := "Xming;.*;;1;0;0;0;0;0;"
   Config_rule_#8   := "CabinetWClass;.*;;1;0;0;0;1;0;"
   Config_rule_#9   := "OperationStatusWindow;.*;;1;0;0;1;1;0;"
   Config_rule_#10  := "Chrome_WidgetWin_1;.*;;1;0;0;0;1;0;"
-  Config_rule_#11  := "Chrome_WidgetWin_1;.*;Window_isPopup;1;0;0;1;1;0;"
+  Config_rule_#11  := "Chrome_WidgetWin_1;.*;Window_isPopup;0;0;0;1;1;0;"
   Config_rule_#12  := "Chrome_RenderWidgetHostHWND;.*;;0;0;0;1;1;0;"
   Config_rule_#13  := "IEFrame;.*Internet Explorer;;1;0;0;0;1;0;"
   Config_rule_#14  := "MozillaWindowClass;.*Mozilla Firefox;;1;0;0;0;1;0;"
diff --git a/src/Debug.ahk b/src/Debug.ahk
index 5c2e25c..8d503a9 100644
--- a/src/Debug.ahk
+++ b/src/Debug.ahk
@@ -51,7 +51,7 @@ Debug_logManagedWindowList()
   Local wndIds
 
   Debug_logMessage("Window dump for manager")
-  Debug_logMessage("ID`t`tH W A F D R G M`tTags`tX`tY`tW`tH`tStyle`t`tProc / Class / Title", 0, False)
+  Debug_logMessage("ID     `tH W A F D R G M Tags`tX   `tY   `tW   `tH   `tStyle     `tProc / Class / Title", 0, False)
 
   StringTrimRight, wndIds, Manager_managedWndIds, 1
   Loop, PARSE, wndIds, `;
@@ -77,16 +77,15 @@ Debug_logMessage(text, level = 1, includeTimestamp = True)
   }
 }
 
-Debug_logViewWindowList()
-{
+Debug_logViewWindowList() {
   Local v, wndIds
 
   v := Monitor_#%Manager_aMonitor%_aView_#1
   Debug_logMessage("Window dump for active view (" . Manager_aMonitor . ", " . v . ")")
-  Debug_logMessage("ID`t`tH W A F D R G M`tTags`tX`tY`tW`tH`tStyle`t`tProc / Class / Title", 0, False)
+  Debug_logMessage("ID     `tH W A F D R G M Tags`tX   `tY   `tW   `tH   `tStyle     `tProc / Class / Title", 0, False)
 
   StringTrimRight, wndIds, View_#%Manager_aMonitor%_#%v%_wndIds, 1
-  Loop, PARSE, wndIds, `;
+  Loop, Parse, wndIds, `;
   {
     Debug_logWindowInfo(A_LoopField)
   }
@@ -142,7 +141,7 @@ Debug_logWindowInfo(wndId)
 
   text := wndId "`t"
   text .= isHidden " " isWinFocus " " isBugnActive " " isFloating " " isDecorated " " isResponsive " " isGhost " "
-  text .= Window_#%wndId%_monitor "`t" Window_#%wndId%_tags "`t"
+  text .= Window_#%wndId%_monitor " " Window_#%wndId%_tags "   `t"
   text .= wndX "`t" wndY "`t" wndW "`t" wndH "`t" wndStyle "`t" wndPName " [" wndPId "] / " wndClass " / " wndTitle
   Debug_logMessage(text , 0, False)
 }
diff --git a/src/Manager.ahk b/src/Manager.ahk
index 4de6187..25805f3 100644
--- a/src/Manager.ahk
+++ b/src/Manager.ahk
@@ -89,7 +89,7 @@ Manager_activateMonitor(i, d = 0) {
 }
 
 Manager_applyRules(wndId, ByRef isManaged, ByRef m, ByRef tags, ByRef isFloating, ByRef isDecorated, ByRef hideTitle, ByRef action) {
-  Local i, mouseX, mouseY, wndClass, wndHeight, wndTitle, wndWidth, wndX, wndY
+  Local i, mouseX, mouseY, wndClass, wndTitle
   Local rule0, rule1, rule2, rule3, rule4, rule5, rule6, rule7, rule8, rule9, rule10
 
   isManaged   := True
@@ -102,7 +102,6 @@ Manager_applyRules(wndId, ByRef isManaged, ByRef m, ByRef tags, ByRef isFloating
 
   WinGetClass, wndClass, ahk_id %wndId%
   WinGetTitle, wndTitle, ahk_id %wndId%
-  WinGetPos, wndX, wndY, wndWidth, wndHeight, ahk_id %wndId%
   If (wndClass Or wndTitle) {
     Loop, % Config_ruleCount {
       ;; The rules are traversed in reverse order.
@@ -125,7 +124,7 @@ Manager_applyRules(wndId, ByRef isManaged, ByRef m, ByRef tags, ByRef isFloating
     If wndTitle
       hideTitle := True
   }
-  Debug_logMessage("DEBUG[3] Manager_applyRules(wndId: " wndId ", isManaged: " isManaged ", m: " m ", tags: " tags ", isFloating: " isFloating ", isDecorated: " isDecorated ", hideTitle: " hideTitle ", action: " action "); class: " wndClass ", title: " wndTitle ", x: " wndX ", y: " wndY, 3)
+  Debug_logMessage("DEBUG[3] Manager_applyRules(wndId: " wndId ", isManaged: " isManaged ", m: " m ", tags: " tags ", isFloating: " isFloating ", isDecorated: " isDecorated ", hideTitle: " hideTitle ", action: " action "); class: " wndClass ", title: " wndTitle, 3)
 }
 
 Manager_cleanup()
@@ -549,14 +548,14 @@ Manager_onShellMessage(wParam, lParam) {
 
   ;; MISSED MESSAGES? FIND ADDITIONAL WINDOWS.
   ;; !! THIS CODE CURRENTLY DOES SOME AWEFUL THINGS!
-;  WinGet, wndId, List, , ,
-;  Loop, % wndId {
-;    If Not InStr(Manager_allWndIds, wndId%A_Index% ";") {
-;      a := Manager_manage(Manager_aMonitor, Monitor_#%Manager_aMonitor%_aView_#1, wndId%A_Index%)
-;      If a
-;        updateView := a
-;    }
-;  }
+  WinGet, wndId, List, , ,
+  Loop, % wndId {
+    If Not InStr(Manager_allWndIds, wndId%A_Index% ";") {
+      a := Manager_manage(Manager_aMonitor, Monitor_#%Manager_aMonitor%_aView_#1, wndId%A_Index%)
+      If a
+        updateView := a
+    }
+  }
 
   ;; IN MOST CASES DO THE FOLLOWING.
   If updateView {
diff --git a/src/Window.ahk b/src/Window.ahk
index 7f5fdff..a04a7f1 100644
--- a/src/Window.ahk
+++ b/src/Window.ahk
@@ -27,6 +27,13 @@ Window_activate(wndId) {
   }
 }
 
+Window_clipsSiblings(wndId) {
+  WS_CLIPSIBLINGS = 0x04000000
+  WinGet, wndStyle, Style, ahk_id %wndId%
+
+  Return, (wndStyle & WS_CLIPSIBLINGS)
+}
+
 Window_close(wndId) {
   If Window_isHung(wndId) {
     Debug_logMessage("DEBUG[2] Window_close: Potentially hung window " . wndId, 2)
@@ -71,7 +78,7 @@ Window_isChild(wndId) {
   WS_POPUP = 0x40000000
   WinGet, wndStyle, Style, ahk_id %wndId%
 
-  Return, wndStyle & WS_POPUP
+  Return, (wndStyle & WS_POPUP)
 }
 
 Window_isElevated(wndId) {
@@ -126,6 +133,18 @@ Window_isHung(wndId) {
     Return, 0
 }
 
+Window_isNotVisible(wndId) {
+  WS_VISIBLE = 0x10000000
+  WinGet, wndStyle, Style, ahk_id %wndId%
+  If (wndStyle & WS_VISIBLE) {
+    WinGetPos, wndX, wndY, wndW, wndH, ahk_id %wndId%
+    hasDimensions := wndW And wndH
+    isOnMonitor := Monitor_get(wndX, wndY) Or Monitor_get(wndX + wndW, wndY) Or Monitor_get(wndX + wndW, wndY + wndH) Or Monitor_get(wndX, wndY + wndH)
+    Return, (Not hasDimensions Or Not isOnMonitor)
+  } Else
+    Return, True
+}
+
 Window_isPopup(wndId) {
   WS_POPUP = 0x80000000
   WinGet, wndStyle, Style, ahk_id %wndId%