Index: doc/Class.3
===================================================================
diff -u -rc210a16eea562921715652f023bc6d07e4e25ed2 -r8f64a468d8bb53f2ba317c8c738c2d3a24243980
--- doc/Class.3	(.../Class.3)	(revision c210a16eea562921715652f023bc6d07e4e25ed2)
+++ doc/Class.3	(.../Class.3)	(revision 8f64a468d8bb53f2ba317c8c738c2d3a24243980)
@@ -988,8 +988,11 @@
 \fIobj\fR \fIpropertyName\fR \fBadd\fR \fIelement\fR ?\fIindex\fR?
 Adding \fIelement\fR to the managed list value, at the list position given by \fIindex\fR (by default: 0)\&.
 .TP
-\fIobj\fR \fIpropertyName\fR \fBdelete\fR \fIelementPattern\fR
-Removing one or multiple elements from the managed list value which match \fIelementPattern\fR\&. \fIelementPattern\fR can contain matching characters (see \fBstring match\fR)\&.
+\fIobj\fR \fIpropertyName\fR \fBdelete\fR ?\fB-nocomplain\fR? \fIelementPattern\fR
+Removing the first occurrence of an element from the managed list
+value which matches \fIelementPattern\fR\&. \fIelementPattern\fR can
+contain matching characters (see \fBstring match\fR)\&. An error will
+be thrown if there is no match, unless \fB-nocomplain\fR is set\&.
 .RE
 .sp
 By setting \fB-configurable\fR to \fBtrue\fR (the default), the
@@ -1093,10 +1096,11 @@
 \fIobj\fR \fIvariableName\fR \fBadd\fR \fIelement\fR ?\fIindex\fR?
 Adding \fIelement\fR to the managed list value, at the list position given by \fIindex\fR (by default: 0)\&.
 .TP
-\fIobj\fR \fIvariableName\fR \fBdelete\fR \fIelementPattern\fR
-Removing one or multiple elements from the managed list value which
-match \fIelementPattern\fR\&. \fIelementPattern\fR can contain matching
-characters (see \fBstring match\fR)\&.
+\fIobj\fR \fIvariableName\fR \fBdelete\fR ?\fB-nocomplain\fR? \fIelementPattern\fR
+Removing the first occurrence of an element from the managed list
+value which matches \fIelementPattern\fR\&. \fIelementPattern\fR can
+contain matching characters (see \fBstring match\fR)\&. An error will
+be thrown if there is no match, unless \fB-nocomplain\fR is set\&.
 .RE
 .sp
 By setting \fB-configurable\fR to \fBtrue\fR, the variable can be
Index: doc/Object.3
===================================================================
diff -u -rc210a16eea562921715652f023bc6d07e4e25ed2 -r8f64a468d8bb53f2ba317c8c738c2d3a24243980
--- doc/Object.3	(.../Object.3)	(revision c210a16eea562921715652f023bc6d07e4e25ed2)
+++ doc/Object.3	(.../Object.3)	(revision 8f64a468d8bb53f2ba317c8c738c2d3a24243980)
@@ -1287,8 +1287,11 @@
 \fIobj\fR \fIpropertyName\fR \fBadd\fR \fIelement\fR ?\fIindex\fR?
 Adding \fIelement\fR to the managed list value, at the list position given by \fIindex\fR (by default: 0)\&.
 .TP
-\fIobj\fR \fIpropertyName\fR \fBdelete\fR \fIelementPattern\fR
-Removing one or multiple elements from the managed list value which match \fIelementPattern\fR\&. \fIelementPattern\fR can contain matching characters (see \fBstring match\fR)\&.
+\fIobj\fR \fIpropertyName\fR \fBdelete\fR ?\fB-nocomplain\fR? \fIelementPattern\fR
+Removing the first occurrence of an element from the managed list
+value which matches \fIelementPattern\fR\&. \fIelementPattern\fR can
+contain matching characters (see \fBstring match\fR)\&. An error will
+be thrown if there is no match, unless \fB-nocomplain\fR is set\&.
 .RE
 .sp
 By setting \fB-configurable\fR to \fBtrue\fR (the default), the
@@ -1430,10 +1433,11 @@
 \fIobj\fR \fIvariableName\fR \fBadd\fR \fIelement\fR ?\fIindex\fR?
 Adding \fIelement\fR to the managed list value, at the list position given by \fIindex\fR (by default: 0)\&.
 .TP
-\fIobj\fR \fIvariableName\fR \fBdelete\fR \fIelementPattern\fR
-Removing one or multiple elements from the managed list value which
-match \fIelementPattern\fR\&. \fIelementPattern\fR can contain matching
-characters (see \fBstring match\fR)\&.
+\fIobj\fR \fIvariableName\fR \fBdelete\fR ?\fB-nocomplain\fR? \fIelementPattern\fR
+Removing the first occurrence of an element from the managed list
+value which matches \fIelementPattern\fR\&. \fIelementPattern\fR can
+contain matching characters (see \fBstring match\fR)\&. An error will
+be thrown if there is no match, unless \fB-nocomplain\fR is set\&.
 .RE
 .sp
 By setting \fB-configurable\fR to \fBtrue\fR, the variable can be
Index: doc/property.man.inc
===================================================================
diff -u -rc210a16eea562921715652f023bc6d07e4e25ed2 -r8f64a468d8bb53f2ba317c8c738c2d3a24243980
--- doc/property.man.inc	(.../property.man.inc)	(revision c210a16eea562921715652f023bc6d07e4e25ed2)
+++ doc/property.man.inc	(.../property.man.inc)	(revision 8f64a468d8bb53f2ba317c8c738c2d3a24243980)
@@ -57,8 +57,12 @@
 [list_begin definitions]
 [def "[arg obj] [arg propertyName] [method add] [arg element] [opt [arg index]]"]
 Adding [arg element] to the managed list value, at the list position given by [arg index] (by default: 0).
-[def "[arg obj] [arg propertyName] [method delete] [arg elementPattern]"]
-Removing one or multiple elements from the managed list value which match [arg elementPattern]. [arg elementPattern] can contain matching characters (see [cmd "string match"]).
+[def "[arg obj] [arg propertyName] [method delete] [opt [option -nocomplain]] [arg elementPattern]"]
+Removing the first occurrence of an element from the managed list
+value which matches [arg elementPattern]. [arg elementPattern] can
+contain matching characters (see [cmd "string match"]). An error will
+be thrown if there is no match, unless [option -nocomplain] is set.
+
 [list_end]
 
 
Index: doc/variable.man.inc
===================================================================
diff -u -rc210a16eea562921715652f023bc6d07e4e25ed2 -r8f64a468d8bb53f2ba317c8c738c2d3a24243980
--- doc/variable.man.inc	(.../variable.man.inc)	(revision c210a16eea562921715652f023bc6d07e4e25ed2)
+++ doc/variable.man.inc	(.../variable.man.inc)	(revision 8f64a468d8bb53f2ba317c8c738c2d3a24243980)
@@ -50,10 +50,12 @@
 [list_begin definitions]
 [def "[arg obj] [arg variableName] [method add] [arg element] [opt [arg index]]"]
 Adding [arg element] to the managed list value, at the list position given by [arg index] (by default: 0).
-[def "[arg obj] [arg variableName] [method delete] [arg elementPattern]"]
-Removing one or multiple elements from the managed list value which
-match [arg elementPattern]. [arg elementPattern] can contain matching
-characters (see [cmd "string match"]).
+[def "[arg obj] [arg variableName] [method delete] [opt [option -nocomplain]] [arg elementPattern]"]
+Removing the first occurrence of an element from the managed list
+value which matches [arg elementPattern]. [arg elementPattern] can
+contain matching characters (see [cmd "string match"]). An error will
+be thrown if there is no match, unless [option -nocomplain] is set.
+
 [list_end]
 
 [para]
Index: library/nx/nx.tcl
===================================================================
diff -u -r470bd5f54e0da47e4eda094ee9f4aa2ba7af18f1 -r8f64a468d8bb53f2ba317c8c738c2d3a24243980
--- library/nx/nx.tcl	(.../nx.tcl)	(revision 470bd5f54e0da47e4eda094ee9f4aa2ba7af18f1)
+++ library/nx/nx.tcl	(.../nx.tcl)	(revision 8f64a468d8bb53f2ba317c8c738c2d3a24243980)
@@ -2040,8 +2040,8 @@
       set vspec [:namedParameterSpec {} value $options_single]
       set addArgs [list obj prop $vspec {pos 0}]
       :public object method value=add $addArgs {::nsf::next [list $obj $prop $value $pos]}
-      set delArgs [list -nocomplain:switch obj prop $vspec]
-      :public object method value=delete $delArgs {::nsf::next [list -nocomplain=$nocomplain $obj $prop $value]}
+      set delArgs [list obj prop -nocomplain:switch $vspec]
+      :public object method value=delete $delArgs {::nsf::next [list $obj $prop -nocomplain=$nocomplain $value]}
     } else {
       # TODO should we deactivate add/delete?
     }
@@ -2198,11 +2198,15 @@
     }
   }
 
-  ::nx::VariableSlot public method value=delete {-nocomplain:switch obj prop value} {
+  ::nx::VariableSlot public method value=delete {obj prop -nocomplain:switch value} {
     set old [::nsf::var::get $obj $prop]
     set p [lsearch -glob $old $value]
-    if {$p>-1} {::nsf::var::set $obj $prop [lreplace $old $p $p]} else {
-      return -code error "$value is not a $prop of $obj (valid are: $old)"
+    if {$p > -1} {
+      ::nsf::var::set $obj $prop [lreplace $old $p $p]
+    } elseif {!$nocomplain} {
+      return -code error "$obj: '$value' is not in variable '$prop' (values are: '$old')"
+    } else {
+      return $old
     }
   }
 
Index: tests/parameters.test
===================================================================
diff -u -r470bd5f54e0da47e4eda094ee9f4aa2ba7af18f1 -r8f64a468d8bb53f2ba317c8c738c2d3a24243980
--- tests/parameters.test	(.../parameters.test)	(revision 470bd5f54e0da47e4eda094ee9f4aa2ba7af18f1)
+++ tests/parameters.test	(.../parameters.test)	(revision 8f64a468d8bb53f2ba317c8c738c2d3a24243980)
@@ -1298,6 +1298,10 @@
   set count [nx::test cget -count]
   nx::test configure -count 1
   ? {p2 sexes delete female} {m m}
+  ? {p2 sexes delete female} {::p2: 'f' is not in variable 'sexes' (values are: 'm m')}
+  ? {p2 sexes delete -nocomplain female} {m m}
+  ? {p2 sexes delete -nocomplain male} {m}
+  ? {p2 sexes get} {m}
   nx::test configure -count $count
 
   Person public method bar {s:sex,0..*,slot=::Person::slot::sexes,convert} {return $s}
Index: tests/properties.test
===================================================================
diff -u -r275da34d3d7a874a451eced58242b738c8a37d1a -r8f64a468d8bb53f2ba317c8c738c2d3a24243980
--- tests/properties.test	(.../properties.test)	(revision 275da34d3d7a874a451eced58242b738c8a37d1a)
+++ tests/properties.test	(.../properties.test)	(revision 8f64a468d8bb53f2ba317c8c738c2d3a24243980)
@@ -342,6 +342,14 @@
   ? {c1 eval {:d add x}} {::c1: unable to dispatch method 'd'}
   ? {c1 add-local d x} {x d1}
   ? {c1 e add x} {x e1}
+  ? {c1 e delete x} {e1}
+  ? {c1 e get} {e1}
+  ? {c1 e delete -nocomplain x} {e1}
+  ? {c1 e delete x} "::c1: 'x' is not in variable 'e' (values are: 'e1')"
+  ? {c1 e delete -nocomplain e1} ""
+  ? {c1 e get} ""
+  ? {c1 e unset} ""
+  ? {c1 e get} {can't read "e": no such variable}
 
   #
   # check incremental operations for variables
@@ -355,8 +363,15 @@
   ? {c1 eval {:vd add x}} {::c1: unable to dispatch method 'vd'}
   ? {c1 add-local vd x} {x vd1}
   ? {c1 ve add x} {x ve1}
+  ? {c1 ve delete x} {ve1}
+  ? {c1 ve get} {ve1}
+  ? {c1 ve delete -nocomplain x} {ve1}
+  ? {c1 ve delete x} "::c1: 'x' is not in variable 've' (values are: 've1')"
+  ? {c1 ve delete -nocomplain ve1} ""
+  ? {c1 ve get} ""
+  ? {c1 ve unset} ""
+  ? {c1 ve get} {can't read "ve": no such variable}
 
-
   #
   # The accessor should be a forwarder due to incremental
   #