Index: openacs-4/packages/acs-core-docs/www/tutorial-categories.adp
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-core-docs/www/tutorial-categories.adp,v
diff -u -N -r1.4.2.1 -r1.4.2.2
--- openacs-4/packages/acs-core-docs/www/tutorial-categories.adp	2 Mar 2019 19:30:06 -0000	1.4.2.1
+++ openacs-4/packages/acs-core-docs/www/tutorial-categories.adp	29 Nov 2019 14:28:48 -0000	1.4.2.2
@@ -63,7 +63,7 @@
                         # extend the form to support categories
                         set package_id [ad_conn package_id]
                             
-                        category::ad_form::add_widgets -form_name note -container_object_id $package_id -categorized_object_id [value_if_exists item_id]
+                        category::ad_form::add_widgets -form_name note -container_object_id $package_id -categorized_object_id [expr {[info exists item_id] ? $item_id : ""}]
 
                         ad_form -extend -name note -on_submit {
                                 set category_ids [category::ad_form::get_categories -container_object_id $package_id]
Index: openacs-4/packages/acs-core-docs/www/tutorial-categories.html
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-core-docs/www/tutorial-categories.html,v
diff -u -N -r1.17.2.1 -r1.17.2.2
--- openacs-4/packages/acs-core-docs/www/tutorial-categories.html	2 Mar 2019 19:30:06 -0000	1.17.2.1
+++ openacs-4/packages/acs-core-docs/www/tutorial-categories.html	29 Nov 2019 14:28:48 -0000	1.17.2.2
@@ -65,7 +65,7 @@
 			# extend the form to support categories
 			set package_id [ad_conn package_id]
 			    
-    			category::ad_form::add_widgets -form_name note -container_object_id $package_id -categorized_object_id [value_if_exists item_id]
+    			category::ad_form::add_widgets -form_name note -container_object_id $package_id -categorized_object_id [expr {[info exists item_id] ? $item_id : ""}]
 
     			ad_form -extend -name note -on_submit {
         			set category_ids [category::ad_form::get_categories -container_object_id $package_id]
Index: openacs-4/packages/acs-core-docs/www/xml/developers-guide/tutorial-advanced.xml
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-core-docs/www/xml/developers-guide/tutorial-advanced.xml,v
diff -u -N -r1.60.2.5 -r1.60.2.6
--- openacs-4/packages/acs-core-docs/www/xml/developers-guide/tutorial-advanced.xml	22 Nov 2019 16:30:46 -0000	1.60.2.5
+++ openacs-4/packages/acs-core-docs/www/xml/developers-guide/tutorial-advanced.xml	29 Nov 2019 14:28:48 -0000	1.60.2.6
@@ -550,7 +550,7 @@
 			# extend the form to support categories
 			set package_id [ad_conn package_id]
 			    
-    			category::ad_form::add_widgets -form_name note -container_object_id $package_id -categorized_object_id [value_if_exists item_id]
+    			category::ad_form::add_widgets -form_name note -container_object_id $package_id -categorized_object_id [expr {[info exists item_id] ? $item_id : ""}]
 
     			ad_form -extend -name note -on_submit {
         			set category_ids [category::ad_form::get_categories -container_object_id $package_id]
Index: openacs-4/packages/acs-tcl/tcl/utilities-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/utilities-procs.tcl,v
diff -u -N -r1.189.2.39 -r1.189.2.40
--- openacs-4/packages/acs-tcl/tcl/utilities-procs.tcl	29 Nov 2019 13:50:46 -0000	1.189.2.39
+++ openacs-4/packages/acs-tcl/tcl/utilities-procs.tcl	29 Nov 2019 14:28:48 -0000	1.189.2.40
@@ -2781,10 +2781,15 @@
     return [regexp -nocase {^(http|https|ftp)://[^ ].+} [string trim $query_url]]
 }
 
-ad_proc -public value_if_exists { var_name } {
+ad_proc -deprecated value_if_exists { var_name } {
     If the specified variable exists in the calling environment,
     returns the value of that variable. Otherwise, returns the
     empty_string.
+
+    DEPRECATED: this proc does not respect OpenACS naming convention
+    and can be replaced with a plain tcl oneliner.
+
+    @see plain tcl idioms
 } {
     upvar $var_name $var_name
     if { [info exists $var_name] } {
Index: openacs-4/packages/faq/www/admin/q-and-a-add-edit.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/faq/www/admin/q-and-a-add-edit.tcl,v
diff -u -N -r1.12 -r1.12.2.1
--- openacs-4/packages/faq/www/admin/q-and-a-add-edit.tcl	7 Aug 2017 23:48:10 -0000	1.12
+++ openacs-4/packages/faq/www/admin/q-and-a-add-edit.tcl	29 Nov 2019 14:28:48 -0000	1.12.2.1
@@ -68,7 +68,7 @@
     set category_map_url [export_vars -base "[site_node::get_package_url -package_key categories]cadmin/one-object" { { object_id $package_id } }]
 
     #extend the form to support categories
-    category::ad_form::add_widgets -form_name new_quest_answ -container_object_id $package_id -categorized_object_id [value_if_exists entry_id]
+    category::ad_form::add_widgets -form_name new_quest_answ -container_object_id $package_id -categorized_object_id [expr {[info exists entry_id] ? $entry_id : ""}]
 
     ad_form -extend -name new_quest_answ -edit_request {
         db_1row q $select_sql_query