diff --git a/app/Controllers/Attributes.php b/app/Controllers/Attributes.php
index 2b7cd5f61..e3a8c710f 100644
--- a/app/Controllers/Attributes.php
+++ b/app/Controllers/Attributes.php
@@ -55,7 +55,7 @@ class Attributes extends Secure_Controller
 	/**
 	 * @return void
 	 */
-	public function save_attribute_value(): void
+	public function postSave_attribute_value(): void
 	{
 		$success = $this->attribute->save_value(
 			$this->request->getPost('attribute_value', FILTER_SANITIZE_STRING),
@@ -70,7 +70,7 @@ class Attributes extends Secure_Controller
 	/**
 	 * @return void
 	 */
-	public function delete_attribute_value(): void
+	public function postDelete_attribute_value(): void
 	{
 		$success = $this->attribute->delete_value(
 			$this->request->getPost('attribute_value', FILTER_SANITIZE_STRING),
@@ -84,7 +84,7 @@ class Attributes extends Secure_Controller
 	 * @param int $definition_id
 	 * @return void
 	 */
-	public function save_definition(int $definition_id = NO_DEFINITION_ID): void
+	public function postSave_definition(int $definition_id = NO_DEFINITION_ID): void
 	{
 		$definition_flags = 0;
 
@@ -144,7 +144,7 @@ class Attributes extends Secure_Controller
 			echo json_encode([
 				'success' => FALSE,
 				'message' => lang('Attributes.definition_error_adding_updating', ['definition_name' => $definition_name]),
-				'id' => -1
+				'id' => NEW_ENTRY
 			]);
 		}
 	}
@@ -204,12 +204,12 @@ class Attributes extends Secure_Controller
 		echo view('attributes/form', $data);
 	}
 
-	public function delete_value(int $attribute_id): bool	//TODO: This function appears to never be used in the codebase.  Is it needed?
+	public function postDelete_value(int $attribute_id): bool	//TODO: This function appears to never be used in the codebase.  Is it needed?
 	{
 		return $this->attribute->delete_value($attribute_id, NO_DEFINITION_ID);
 	}
 
-	public function delete(): void
+	public function postDelete(): void
 	{
 		$attributes_to_delete = $this->request->getPost('ids', FILTER_SANITIZE_STRING);
 
diff --git a/app/Controllers/Cashups.php b/app/Controllers/Cashups.php
index 8ccee018d..0e5863e56 100644
--- a/app/Controllers/Cashups.php
+++ b/app/Controllers/Cashups.php
@@ -62,7 +62,7 @@ class Cashups extends Secure_Controller
 		echo json_encode(['total' => $total_rows, 'rows' => $data_rows]);
 	}
 
-	public function getView(int $cashup_id = -1): void	//TODO: Need to replace -1 with a constant in constants.php
+	public function getView(int $cashup_id = NEW_ENTRY): void
 	{
 		$data = [];
 
@@ -186,7 +186,7 @@ class Cashups extends Secure_Controller
 		echo json_encode($data_row);
 	}
 
-	public function save(int $cashup_id = -1): void	//TODO: Need to replace -1 with a constant in constants.php
+	public function postSave(int $cashup_id = NEW_ENTRY): void
 	{
 		$open_date = $this->request->getPost('open_date', FILTER_SANITIZE_STRING);
 		$open_date_formatter = date_create_from_format($this->config['dateformat'] . ' ' . $this->config['timeformat'], $open_date);
@@ -214,7 +214,7 @@ class Cashups extends Secure_Controller
 		if($this->cashup->save_value($cash_up_data, $cashup_id))
 		{
 			//New cashup_id
-			if($cashup_id == -1)//TODO: Need to replace -1 with a constant in constants.php
+			if($cashup_id == NEW_ENTRY)
 			{
 				echo json_encode(['success' => TRUE, 'message' => lang('Cashups.successful_adding'), 'id' => $cash_up_data['cashup_id']]);
 			}
@@ -225,11 +225,11 @@ class Cashups extends Secure_Controller
 		}
 		else//failure
 		{
-			echo json_encode(['success' => FALSE, 'message' => lang('Cashups.error_adding_updating'), 'id' => -1]);//TODO: Need to replace -1 with a constant in constants.php
+			echo json_encode(['success' => FALSE, 'message' => lang('Cashups.error_adding_updating'), 'id' => NEW_ENTRY]);
 		}
 	}
 
-	public function delete(): void
+	public function postDelete(): void
 	{
 		$cash_ups_to_delete = $this->request->getPost('ids', FILTER_SANITIZE_STRING);
 
diff --git a/app/Controllers/Employees.php b/app/Controllers/Employees.php
index 9919964dc..8025cff21 100644
--- a/app/Controllers/Employees.php
+++ b/app/Controllers/Employees.php
@@ -62,7 +62,7 @@ class Employees extends Persons
 	/**
 	 * Loads the employee edit form
 	 */
-	public function getView(int $employee_id = -1): void	//TODO: Replace -1 with a constant
+	public function getView(int $employee_id = NEW_ENTRY): void
 	{
 		$person_info = $this->employee->get_info($employee_id);
 		foreach(get_object_vars($person_info) as $property => $value)
@@ -98,7 +98,7 @@ class Employees extends Persons
 	/**
 	 * Inserts/updates an employee
 	 */
-	public function save(int $employee_id = -1): void	//TODO: Replace -1 with a constant
+	public function postSave(int $employee_id = NEW_ENTRY): void
 	{
 		$first_name = $this->request->getPost('first_name', FILTER_SANITIZE_STRING);	//TODO: duplicated code
 		$last_name = $this->request->getPost('last_name', FILTER_SANITIZE_STRING);
@@ -162,7 +162,7 @@ class Employees extends Persons
 		if($this->employee->save_employee($person_data, $employee_data, $grants_array, $employee_id))
 		{
 			// New employee
-			if($employee_id == -1)
+			if($employee_id == NEW_ENTRY)
 			{
 				echo json_encode ([
 					'success' => TRUE,
@@ -184,7 +184,7 @@ class Employees extends Persons
 			echo json_encode ([
 				'success' => FALSE,
 				'message' => lang('Employees.error_adding_updating') . ' ' . $first_name . ' ' . $last_name,
-				'id' => -1
+				'id' => NEW_ENTRY
 			]);
 		}
 	}
@@ -192,7 +192,7 @@ class Employees extends Persons
 	/**
 	 * This deletes employees from the employees table
 	 */
-	public function delete(): void
+	public function postDelete(): void
 	{
 		$employees_to_delete = $this->request->getPost('ids', FILTER_SANITIZE_STRING);
 
diff --git a/app/Controllers/Expenses.php b/app/Controllers/Expenses.php
index 2a1911134..ed2a462d3 100644
--- a/app/Controllers/Expenses.php
+++ b/app/Controllers/Expenses.php
@@ -76,7 +76,7 @@ class Expenses extends Secure_Controller
 		echo json_encode (['total' => $total_rows, 'rows' => $data_rows, 'payment_summary' => $payment_summary]);
 	}
 
-	public function getView(int $expense_id = -1): void	//TODO: Replace -1 with a constant
+	public function getView(int $expense_id = NEW_ENTRY): void
 	{
 		$data = [];	//TODO: Duplicated code
 
@@ -133,7 +133,7 @@ class Expenses extends Secure_Controller
 		echo json_encode($data_row);
 	}
 
-	public function save(int $expense_id = -1): void	//TODO: Replace -1 with a constant
+	public function postSave(int $expense_id = NEW_ENTRY): void
 	{
 		$config = config('OSPOS')->settings;
 		$newdate = $this->request->getPost('date', FILTER_SANITIZE_STRING);
@@ -156,7 +156,7 @@ class Expenses extends Secure_Controller
 		if($this->expense->save_value($expense_data, $expense_id))
 		{
 			//New Expense
-			if($expense_id == -1)
+			if($expense_id == NEW_ENTRY)
 			{
 				echo json_encode (['success' => TRUE, 'message' => lang('Expenses.successful_adding'), 'id' => $expense_data['expense_id']]);
 			}
@@ -167,7 +167,7 @@ class Expenses extends Secure_Controller
 		}
 		else//failure
 		{
-			echo json_encode (['success' => FALSE, 'message' => lang('Expenses.error_adding_updating'), 'id' => -1]);	//TODO: Need to replace -1 with a constant
+			echo json_encode (['success' => FALSE, 'message' => lang('Expenses.error_adding_updating'), 'id' => NEW_ENTRY]);
 		}
 	}
 
@@ -178,7 +178,7 @@ class Expenses extends Secure_Controller
 		echo json_encode (['success' => $parsed_value !== FALSE]);
 	}
 
-	public function delete(): void
+	public function postDelete(): void
 	{
 		$expenses_to_delete = $this->request->getPost('ids', FILTER_SANITIZE_STRING);
 
diff --git a/app/Controllers/Expenses_categories.php b/app/Controllers/Expenses_categories.php
index d7d4ee519..ce99904cc 100644
--- a/app/Controllers/Expenses_categories.php
+++ b/app/Controllers/Expenses_categories.php
@@ -53,14 +53,14 @@ class Expenses_categories extends Secure_Controller	//TODO: Is this class ever u
 		echo json_encode($data_row);
 	}
 
-	public function getView(int $expense_category_id = -1): void	//TODO: Replace -1 with a constant
+	public function getView(int $expense_category_id = NEW_ENTRY): void
 	{
 		$data['category_info'] = $this->expense_category->get_info($expense_category_id);
 
 		echo view("expenses_categories/form", $data);
 	}
 
-	public function save(int $expense_category_id = -1): void	//TODO: Replace -1 with a constant
+	public function postSave(int $expense_category_id = NEW_ENTRY): void
 	{
 		$expense_category_data = [
 			'category_name' => $this->request->getPost('category_name', FILTER_SANITIZE_STRING),
@@ -70,7 +70,7 @@ class Expenses_categories extends Secure_Controller	//TODO: Is this class ever u
 		if($this->expense_category->save_value($expense_category_data, $expense_category_id))	//TODO: Reflection exception
 		{
 			// New expense_category
-			if($expense_category_id == -1)	//TODO: Replace -1 with a constant.
+			if($expense_category_id == NEW_ENTRY)
 			{
 				echo json_encode ([
 					'success' => TRUE,
@@ -88,16 +88,16 @@ class Expenses_categories extends Secure_Controller	//TODO: Is this class ever u
 			}
 		}
 		else//failure
-		{//TODO: need to replace -1 for a constant
+		{
 			echo json_encode ([
 				'success' => FALSE,
 				'message' => lang('Expenses_categories.error_adding_updating') . ' ' . $expense_category_data['category_name'],
-				'id' => -1
+				'id' => NEW_ENTRY
 			]);
 		}
 	}
 
-	public function delete(): void
+	public function postDelete(): void
 	{
 		$expense_category_to_delete = $this->request->getPost('ids', FILTER_SANITIZE_STRING);
 
diff --git a/app/Controllers/Giftcards.php b/app/Controllers/Giftcards.php
index 76d83f8e1..cf992b182 100644
--- a/app/Controllers/Giftcards.php
+++ b/app/Controllers/Giftcards.php
@@ -71,7 +71,7 @@ class Giftcards extends Secure_Controller
 		echo json_encode($data_row);
 	}
 
-	public function getView(int $giftcard_id = -1): void	//TODO: Need to replace -1 with a constant
+	public function getView(int $giftcard_id = NEW_ENTRY): void
 	{
 		$config = config('OSPOS')->settings;
 		$giftcard_info = $this->giftcard->get_info($giftcard_id);
@@ -93,11 +93,11 @@ class Giftcards extends Secure_Controller
 		echo view("giftcards/form", $data);
 	}
 
-	public function save(int $giftcard_id = -1): void	//TODO: Replace -1 with a constant
+	public function postSave(int $giftcard_id = NEW_ENTRY): void
 	{
 		$giftcard_number = $this->request->getPost('giftcard_number', FILTER_SANITIZE_STRING);
 
-		if($giftcard_id == -1 && trim($giftcard_number) == '')
+		if($giftcard_id == NEW_ENTRY && trim($giftcard_number) == '')
 		{
 			$giftcard_number = $this->giftcard->generate_unique_giftcard_name($this->request->getPost('giftcard_amount', FILTER_SANITIZE_NUMBER_FLOAT, FILTER_FLAG_ALLOW_FRACTION));
 		}
@@ -112,7 +112,7 @@ class Giftcards extends Secure_Controller
 		if($this->giftcard->save_value($giftcard_data, $giftcard_id))
 		{
 			//New giftcard
-			if($giftcard_id == -1)	//TODO: Constant needed
+			if($giftcard_id == NEW_ENTRY)	//TODO: Constant needed
 			{
 				echo json_encode ([
 					'success' => TRUE,
@@ -134,7 +134,7 @@ class Giftcards extends Secure_Controller
 			echo json_encode ([
 				'success' => FALSE,
 				'message' => lang('Giftcards.error_adding_updating') . ' ' . $giftcard_data['giftcard_number'],
-				'id' => -1
+				'id' => NEW_ENTRY
 			]);
 		}
 	}
@@ -150,7 +150,7 @@ class Giftcards extends Secure_Controller
 		echo json_encode (['success' => $parsed_value !== FALSE, 'giftcard_amount' => to_currency_no_money($parsed_value)]);
 	}
 
-	public function delete(): void
+	public function postDelete(): void
 	{
 		$giftcards_to_delete = $this->request->getPost('ids', FILTER_SANITIZE_STRING);
 
diff --git a/app/Controllers/Item_kits.php b/app/Controllers/Item_kits.php
index 2fca99676..cb644b2cc 100644
--- a/app/Controllers/Item_kits.php
+++ b/app/Controllers/Item_kits.php
@@ -111,11 +111,11 @@ class Item_kits extends Secure_Controller
 		echo json_encode(get_item_kit_data_row($item_kit));
 	}
 
-	public function getView(int $item_kit_id = -1): void	//TODO: Replace -1 with a constant
+	public function getView(int $item_kit_id = NEW_ENTRY): void
 	{
 		$info = $this->item_kit->get_info($item_kit_id);
 
-		if($item_kit_id == -1)	//TODO: Replace -1 with a constant
+		if($item_kit_id == NEW_ENTRY)
 		{
 			$info->price_option = '0';
 			$info->print_option = PRINT_ALL;
@@ -150,7 +150,7 @@ class Item_kits extends Secure_Controller
 		echo view("item_kits/form", $data);
 	}
 
-	public function save(int $item_kit_id = -1): void	//TODO: Replace -1 with a constant
+	public function postSave(int $item_kit_id = NEW_ENTRY): void
 	{
 		$item_kit_data = [
 			'name' => $this->request->getPost('name', FILTER_SANITIZE_STRING),
@@ -167,7 +167,7 @@ class Item_kits extends Secure_Controller
 		{
 			$new_item = FALSE;
 			//New item kit
-			if($item_kit_id == -1)	//TODO: Replace -1 with a constant
+			if($item_kit_id == NEW_ENTRY)
 			{
 				$item_kit_id = $item_kit_data['item_kit_id'];
 				$new_item = TRUE;
@@ -213,12 +213,12 @@ class Item_kits extends Secure_Controller
 			echo json_encode ([
 				'success' => FALSE,
 				'message' => lang('Item_kits.error_adding_updating') . ' ' . $item_kit_data['name'],
-				'id' => -1	//TODO: Replace -1 with a constant
+				'id' => NEW_ENTRY
 			]);
 		}
 	}
 
-	public function delete(): void
+	public function postDelete(): void
 	{
 		$item_kits_to_delete = $this->request->getPost('ids', FILTER_SANITIZE_STRING);
 
diff --git a/app/Controllers/Items.php b/app/Controllers/Items.php
index 2274c6a1d..5beba18c9 100644
--- a/app/Controllers/Items.php
+++ b/app/Controllers/Items.php
@@ -242,12 +242,12 @@ class Items extends Secure_Controller
 		echo json_encode($result);
 	}
 
-	public function getView(int $item_id = NEW_ITEM): void	//TODO: Super long function.  Perhaps we need to refactor out some methods.
+	public function getView(int $item_id = NEW_ENTRY): void	//TODO: Super long function.  Perhaps we need to refactor out some methods.
 	{
 		// Set default values
-		if($item_id == null) $item_id = NEW_ITEM;
+		if($item_id == null) $item_id = NEW_ENTRY;
 
-		if($item_id === NEW_ITEM)
+		if($item_id === NEW_ENTRY)
 		{
 			$data = [];
 		}
@@ -275,7 +275,7 @@ class Items extends Secure_Controller
 
 		if($data['allow_temp_item'] === 1)
 		{
-			if($item_id !== NEW_ITEM)
+			if($item_id !== NEW_ENTRY)
 			{
 				if($item_info->item_type != ITEM_TEMP)
 				{
@@ -305,7 +305,7 @@ class Items extends Secure_Controller
 			$data['selected_category'] = $item_info->category;
 		}
 
-		if($item_id === NEW_ITEM)
+		if($item_id === NEW_ENTRY)
 		{
 			$data['default_tax_1_rate'] = $this->config['default_tax_1_rate'];
 			$data['default_tax_2_rate'] = $this->config['default_tax_2_rate'];
@@ -400,14 +400,14 @@ class Items extends Secure_Controller
 		foreach($stock_locations as $location)
 		{
 			$quantity = $this->item_quantity->get_item_quantity($item_id, $location['location_id'])->quantity;
-			$quantity = ($item_id === NEW_ITEM) ? 0 : $quantity;
+			$quantity = ($item_id === NEW_ENTRY) ? 0 : $quantity;
 			$location_array[$location['location_id']] = ['location_name' => $location['location_name'], 'quantity' => $quantity];
 			$data['stock_locations'] = $location_array;
 		}
 
 		$data['selected_low_sell_item_id'] = $item_info->low_sell_item_id;
 
-		if($item_id !== NEW_ITEM && $item_info->item_id !== $item_info->low_sell_item_id)
+		if($item_id !== NEW_ENTRY && $item_info->item_id !== $item_info->low_sell_item_id)
 		{
 			$low_sell_item_info = $this->item->get_info($item_info->low_sell_item_id);
 			$data['selected_low_sell_item'] = implode(NAME_SEPARATOR, [$low_sell_item_info->name, $low_sell_item_info->pack_name]);
@@ -420,7 +420,7 @@ class Items extends Secure_Controller
 		echo view('items/form', $data);
 	}
 
-	public function inventory(int $item_id = NEW_ITEM): void
+	public function inventory(int $item_id = NEW_ENTRY): void
 	{
 		$item_info = $this->item->get_info($item_id);	//TODO: Duplicate code
 
@@ -444,7 +444,7 @@ class Items extends Secure_Controller
 		echo view('items/form_inventory', $data);
 	}
 
-	public function count_details(int $item_id = NEW_ITEM): void
+	public function count_details(int $item_id = NEW_ENTRY): void
 	{
 		$item_info = $this->item->get_info($item_id);	//TODO: Duplicate code
 
@@ -492,7 +492,7 @@ class Items extends Secure_Controller
 		echo view('barcodes/barcode_sheet', $data);
 	}
 
-	public function getAttributes(int $item_id = NEW_ITEM): void
+	public function getAttributes(int $item_id = NEW_ENTRY): void
 	{
 		$data['item_id'] = $item_id;
 		$definition_ids = json_decode($this->request->getPost('definition_ids', FILTER_SANITIZE_STRING), TRUE);
@@ -554,7 +554,7 @@ class Items extends Secure_Controller
 	/**
 	 * @throws ReflectionException
 	 */
-	public function save(int $item_id = NEW_ITEM): void
+	public function postSave(int $item_id = NEW_ENTRY): void
 	{
 		$upload_success = $this->upload_image();
 		$upload_file = $this->request->hasFile('image') ? $this->request->getFile('image') : null;	//TODO: https://codeigniter4.github.io/userguide/incoming/incomingrequest.html#uploaded-files
@@ -621,7 +621,7 @@ class Items extends Secure_Controller
 			$success = TRUE;
 			$new_item = FALSE;
 
-			if($item_id === NEW_ITEM)
+			if($item_id === NEW_ENTRY)
 			{
 				$item_id = $item_data['item_id'];
 				$new_item = TRUE;
@@ -722,7 +722,7 @@ class Items extends Secure_Controller
 		{
 			$message = lang('Items.error_adding_updating') . ' ' . $item_data['name'];
 
-			echo json_encode (['success' => FALSE, 'message' => $message, 'id' => NEW_ITEM]);
+			echo json_encode (['success' => FALSE, 'message' => $message, 'id' => NEW_ENTRY]);
 		}
 	}
 
@@ -778,7 +778,7 @@ class Items extends Secure_Controller
 	 */
 	public function check_kit_exists(): void	//TODO: This function appears to be never called in the code.  Need to confirm.
 	{
-		if($this->request->getPost('item_number', FILTER_SANITIZE_STRING) === NEW_ITEM)
+		if($this->request->getPost('item_number', FILTER_SANITIZE_STRING) === NEW_ENTRY)
 		{
 			$exists = $this->item_kit->item_kit_exists_for_name($this->request->getPost('name', FILTER_SANITIZE_STRING));	//TODO: item_kit_exists_for_name doesn't exist in Item_kit.  I looked at the blame and it appears to have never existed.
 		}
@@ -800,7 +800,7 @@ class Items extends Secure_Controller
 	/**
 	 * @throws ReflectionException
 	 */
-	public function save_inventory($item_id = NEW_ITEM): void
+	public function save_inventory($item_id = NEW_ENTRY): void
 	{
 		$employee_id = $this->employee->get_logged_in_employee_info()->person_id;
 		$cur_item_info = $this->item->get_info($item_id);
@@ -834,7 +834,7 @@ class Items extends Secure_Controller
 		{
 			$message = lang('Items.error_adding_updating') . " $cur_item_info->name";
 
-			echo json_encode (['success' => FALSE, 'message' => $message, 'id' => NEW_ITEM]);
+			echo json_encode (['success' => FALSE, 'message' => $message, 'id' => NEW_ENTRY]);
 		}
 	}
 
@@ -889,7 +889,7 @@ class Items extends Secure_Controller
 	/**
 	 * @throws ReflectionException
 	 */
-	public function delete(): void
+	public function postDelete(): void
 	{
 		$items_to_delete = $this->request->getPost('ids', FILTER_SANITIZE_NUMBER_INT);
 
@@ -941,7 +941,7 @@ class Items extends Secure_Controller
 				$allowed_stock_locations = $this->stock_location->get_allowed_locations();
 				$attribute_definition_names	= $this->attribute->get_definition_names();
 
-				unset($attribute_definition_names[-1]);	//Removes the common_none_selected_text from the array
+				unset($attribute_definition_names[NEW_ENTRY]);	//Removes the common_none_selected_text from the array
 
 				$attribute_data = [];
 
diff --git a/app/Controllers/Messages.php b/app/Controllers/Messages.php
index dd9411fac..938fc8224 100644
--- a/app/Controllers/Messages.php
+++ b/app/Controllers/Messages.php
@@ -30,7 +30,7 @@ class Messages extends Secure_Controller
 		echo view('messages/sms');
 	}
 
-	public function getView(int $person_id = -1): void	//TODO: Replace -1 with a constant
+	public function getView(int $person_id = NEW_ENTRY): void
 	{ 
 		$info = $this->person->get_info($person_id);
 		foreach(get_object_vars($info) as $property => $value)
@@ -65,7 +65,7 @@ class Messages extends Secure_Controller
 	 * @param int $person_id
 	 * @return void
 	 */
-	public function send_form(int $person_id = -1): void	//TODO: Replace -1 with a constant
+	public function send_form(int $person_id = NEW_ENTRY): void
 	{	
 		$phone   = $this->request->getPost('phone', FILTER_SANITIZE_STRING);
 		$message = $this->request->getPost('message', FILTER_SANITIZE_STRING);
@@ -77,7 +77,7 @@ class Messages extends Secure_Controller
 			echo json_encode ([
 				'success' => TRUE,
 				'message' => lang('Messages.successfully_sent') . ' ' . esc($phone),
-				'person_id' => $person_id	//TODO: Replace -1 with a constant
+				'person_id' => $person_id
 			]);
 		}
 		else
@@ -85,7 +85,7 @@ class Messages extends Secure_Controller
 			echo json_encode ([
 				'success' => FALSE,
 				'message' => lang('Messages.unsuccessfully_sent') . ' ' . esc($phone),
-				'person_id' => -1	//TODO: Replace -1 with a constant
+				'person_id' => NEW_ENTRY
 			]);
 		}
 	}
diff --git a/app/Controllers/Receivings.php b/app/Controllers/Receivings.php
index f5b41e513..7403942db 100644
--- a/app/Controllers/Receivings.php
+++ b/app/Controllers/Receivings.php
@@ -223,7 +223,7 @@ class Receivings extends Secure_Controller
 	 * @param $item_number
 	 * @return void
 	 */
-	public function delete_item($item_number): void
+	public function postDelete_item($item_number): void
 	{
 		$this->receiving_lib->delete_item($item_number);
 
@@ -233,7 +233,7 @@ class Receivings extends Secure_Controller
 	/**
 	 * @throws ReflectionException
 	 */
-	public function delete(int $receiving_id = -1, bool $update_inventory = TRUE) : void
+	public function postDelete(int $receiving_id = -1, bool $update_inventory = TRUE) : void
 	{
 		$employee_id = $this->employee->get_logged_in_employee_info()->person_id;
 		$receiving_ids = $receiving_id == -1 ? $this->request->getPost('ids', FILTER_SANITIZE_NUMBER_INT) : [$receiving_id];	//TODO: Replace -1 with constant
diff --git a/app/Controllers/Sales.php b/app/Controllers/Sales.php
index f443b20e3..caf978735 100644
--- a/app/Controllers/Sales.php
+++ b/app/Controllers/Sales.php
@@ -447,7 +447,7 @@ class Sales extends Secure_Controller
 	 * @param string $payment_id
 	 * @return void
 	 */
-	public function delete_payment(string $payment_id): void
+	public function postDelete_payment(string $payment_id): void
 	{
 		$this->sale_lib->delete_payment($payment_id);
 
@@ -463,7 +463,7 @@ class Sales extends Secure_Controller
 
 		// check if any discount is assigned to the selected customer
 		$customer_id = $this->sale_lib->get_customer();
-		if($customer_id != -1)	//TODO: Replace -1 with a constant
+		if($customer_id != NEW_ENTRY)
 		{
 			// load the customer discount if any
 			$customer_discount = $this->customer->get_info($customer_id)->discount;
@@ -594,7 +594,7 @@ class Sales extends Secure_Controller
 	 * @return void
 	 * @throws ReflectionException
 	 */
-	public function delete_item(int $item_id): void
+	public function postDelete_item(int $item_id): void
 	{
 		$this->sale_lib->delete_item($item_id);
 
@@ -740,7 +740,7 @@ class Sales extends Secure_Controller
 			}
 
 
-			if($sale_id == -1 && $this->sale->check_invoice_number_exists($invoice_number))	//TODO: Replace -1 with constant
+			if($sale_id == NEW_ENTRY && $this->sale->check_invoice_number_exists($invoice_number))
 			{
 				$data['error'] = lang('Sales.invoice_number_duplicate', ['invoice_number' => $invoice_number]);
 				$this->_reload($data);
@@ -761,7 +761,7 @@ class Sales extends Secure_Controller
 				// Resort and filter cart lines for printing
 				$data['cart'] = $this->sale_lib->sort_and_filter_cart($data['cart']);
 
-				if($data['sale_id_num'] == -1)
+				if($data['sale_id_num'] == NEW_ENTRY)
 				{
 					$data['error_message'] = lang('Sales.transaction_failed');
 				}
@@ -791,7 +791,7 @@ class Sales extends Secure_Controller
 				$work_order_number = $this->token_lib->render($work_order_format);
 			}
 
-			if($sale_id == -1 && $this->sale->check_work_order_number_exists($work_order_number))
+			if($sale_id == NEW_ENTRY && $this->sale->check_work_order_number_exists($work_order_number))
 			{
 				$data['error'] = lang('Sales.work_order_number_duplicate');
 				$this->_reload($data);
@@ -826,7 +826,7 @@ class Sales extends Secure_Controller
 				$quote_number = $this->token_lib->render($quote_format);
 			}
 
-			if($sale_id == -1 && $this->sale->check_quote_number_exists($quote_number))
+			if($sale_id == NEW_ENTRY && $this->sale->check_quote_number_exists($quote_number))
 			{
 				$data['error'] = lang('Sales.quote_number_duplicate');
 				$this->_reload($data);
@@ -867,7 +867,7 @@ class Sales extends Secure_Controller
 
 			$data['cart'] = $this->sale_lib->sort_and_filter_cart($data['cart']);
 
-			if($data['sale_id_num'] == -1)	//TODO: Replace -1 with a constant
+			if($data['sale_id_num'] == NEW_ENTRY)
 			{
 				$data['error_message'] = lang('Sales.transaction_failed');
 			}
@@ -963,7 +963,7 @@ class Sales extends Secure_Controller
 	{
 		$customer_info = '';
 
-		if($customer_id != -1)
+		if($customer_id != NEW_ENTRY)
 		{
 			$customer_info = $this->customer->get_info($customer_id);
 			$data['customer_id'] = $customer_id;
@@ -1144,8 +1144,8 @@ class Sales extends Secure_Controller
 
 		if($sale_id == '')
 		{
-			$sale_id = -1;
-			$this->session->set('sale_id', -1);	//TODO: replace -1 with a constant
+			$sale_id = NEW_ENTRY;
+			$this->session->set('sale_id', NEW_ENTRY);
 		}
 		$cash_rounding = $this->sale_lib->reset_cash_rounding();
 
@@ -1334,7 +1334,7 @@ class Sales extends Secure_Controller
 	/**
 	 * @throws ReflectionException
 	 */
-	public function delete(int $sale_id = -1, bool $update_inventory = TRUE): void	//TODO: Replace -1 with a constant
+	public function postDelete(int $sale_id = NEW_ENTRY, bool $update_inventory = TRUE): void
 	{
 		$employee_id = $this->employee->get_logged_in_employee_info()->person_id;
 		$has_grant = $this->employee->has_grant('sales_delete', $employee_id);
@@ -1345,7 +1345,7 @@ class Sales extends Secure_Controller
 		}
 		else
 		{
-			$sale_ids = $sale_id == -1 ? $this->request->getPost('ids', FILTER_SANITIZE_NUMBER_INT) : [$sale_id];	//TODO: Replace -1 with a constant
+			$sale_ids = $sale_id == NEW_ENTRY ? $this->request->getPost('ids', FILTER_SANITIZE_NUMBER_INT) : [$sale_id];
 
 			if($this->sale->delete_list($sale_ids, $employee_id, $update_inventory))
 			{
@@ -1362,7 +1362,7 @@ class Sales extends Secure_Controller
 		}
 	}
 
-	public function restore(int $sale_id = -1, bool $update_inventory = TRUE): void	//TODO: Replace -1 with a constant
+	public function restore(int $sale_id = NEW_ENTRY, bool $update_inventory = TRUE): void
 	{
 		$employee_id = $this->employee->get_logged_in_employee_info()->person_id;
 		$has_grant = $this->employee->has_grant('sales_delete', $employee_id);
@@ -1373,7 +1373,7 @@ class Sales extends Secure_Controller
 		}
 		else
 		{
-			$sale_ids = $sale_id == -1 ? $this->request->getPost('ids', FILTER_SANITIZE_NUMBER_INT) : [$sale_id];	//TODO: Replace -1 with a constant
+			$sale_ids = $sale_id == NEW_ENTRY ? $this->request->getPost('ids', FILTER_SANITIZE_NUMBER_INT) : [$sale_id];
 
 			if($this->sale->restore_list($sale_ids, $employee_id, $update_inventory))
 			{
@@ -1396,7 +1396,7 @@ class Sales extends Secure_Controller
 	 * @param int $sale_id
 	 * @throws ReflectionException
 	 */
-	public function save(int $sale_id = -1): void	//TODO: Replace -1 with a constant
+	public function save(int $sale_id = NEW_ENTRY): void
 	{
 		$newdate = $this->request->getPost('date', FILTER_SANITIZE_STRING);
 		$employee_id = $this->employee->get_logged_in_employee_info()->person_id;
@@ -1455,7 +1455,7 @@ class Sales extends Secure_Controller
 			];
 		}
 
-		$payment_id = -1;	//TODO: Replace -1 with a constant
+		$payment_id = NEW_ENTRY;
 		$payment_amount = $this->request->getPost('payment_amount_new', FILTER_SANITIZE_NUMBER_FLOAT, FILTER_FLAG_ALLOW_FRACTION);
 		$payment_type = $this->request->getPost('payment_type_new', FILTER_SANITIZE_STRING);
 
@@ -1508,7 +1508,7 @@ class Sales extends Secure_Controller
 	public function cancel(): void
 	{
 		$sale_id = $this->sale_lib->get_sale_id();
-		if($sale_id != -1 && $sale_id != '')	//TODO: Replace -1 with a constant
+		if($sale_id != NEW_ENTRY && $sale_id != '')
 		{
 			$sale_type = $this->sale_lib->get_sale_type();
 
@@ -1525,7 +1525,7 @@ class Sales extends Secure_Controller
 			else
 			{
 				$this->sale->delete($sale_id);
-				$this->session->set('sale_id', -1);	//TODO: Replace -1 with a constant
+				$this->session->set('sale_id', NEW_ENTRY);
 			}
 		}
 		else
diff --git a/app/Controllers/Suppliers.php b/app/Controllers/Suppliers.php
index 8e41ed6e7..e761cd9a8 100644
--- a/app/Controllers/Suppliers.php
+++ b/app/Controllers/Suppliers.php
@@ -87,7 +87,7 @@ class Suppliers extends Persons
 	/*
 	Loads the supplier edit form
 	*/
-	public function getView(int $supplier_id = -1): void	//TODO: Replace -1 with constant
+	public function getView(int $supplier_id = NEW_ENTRY): void
 	{
 		$info = $this->supplier->get_info($supplier_id);
 		foreach(get_object_vars($info) as $property => $value)
@@ -103,7 +103,7 @@ class Suppliers extends Persons
 	/*
 	Inserts/updates a supplier
 	*/
-	public function save(int $supplier_id = -1): void	//TODO: Replace -1 with constant
+	public function postSave(int $supplier_id = NEW_ENTRY): void
 	{
 		$first_name = $this->request->getPost('first_name', FILTER_SANITIZE_STRING);	//TODO: Duplicate code
 		$last_name = $this->request->getPost('last_name', FILTER_SANITIZE_STRING);
@@ -139,7 +139,7 @@ class Suppliers extends Persons
 		if($this->supplier->save_supplier($person_data, $supplier_data, $supplier_id))
 		{
 			//New supplier
-			if($supplier_id == -1)	//TODO: Replace -1 with a constant
+			if($supplier_id == NEW_ENTRY)
 			{
 				echo json_encode ([
 					'success' => TRUE,
@@ -160,7 +160,7 @@ class Suppliers extends Persons
 			echo json_encode ([
 				'success' => FALSE,
 				'message' => lang('Suppliers.error_adding_updating') . ' ' . 	$supplier_data['company_name'],
-				'id' => -1	//TODO: Replace -1 with a constant
+				'id' => NEW_ENTRY
 			]);
 		}
 	}
@@ -168,7 +168,7 @@ class Suppliers extends Persons
 	/*
 	This deletes suppliers from the suppliers table
 	*/
-	public function delete(): void
+	public function postDelete(): void
 	{
 		$suppliers_to_delete = $this->request->getPost('ids', FILTER_SANITIZE_NUMBER_INT);
 
diff --git a/app/Controllers/Tax_categories.php b/app/Controllers/Tax_categories.php
index 1e3b8be71..2a0daad1f 100644
--- a/app/Controllers/Tax_categories.php
+++ b/app/Controllers/Tax_categories.php
@@ -53,7 +53,7 @@ class Tax_categories extends Secure_Controller
 		echo json_encode($data_row);
 	}
 
-	public function getView(int $tax_category_id = -1): void	//TODO: Need to replace -1 with constant
+	public function getView(int $tax_category_id = NEW_ENTRY): void
 	{
 		$data['tax_category_info'] = $this->tax_category->get_info($tax_category_id);
 
@@ -61,7 +61,7 @@ class Tax_categories extends Secure_Controller
 	}
 
 
-	public function save(int $tax_category_id = -1): void	//TODO: Need to replace -1 with constant
+	public function postSave(int $tax_category_id = NEW_ENTRY): void
 	{
 		$tax_category_data = [
 			'tax_category' => $this->request->getPost('tax_category', FILTER_SANITIZE_STRING),
@@ -72,7 +72,7 @@ class Tax_categories extends Secure_Controller
 		if($this->tax_category->save_value($tax_category_data, $tax_category_id))
 		{
 			// New tax_category_id
-			if($tax_category_id == -1)	//TODO: Need to replace -1 with constant
+			if($tax_category_id == NEW_ENTRY)
 			{
 				echo json_encode ([
 					'success' => TRUE,
@@ -94,12 +94,12 @@ class Tax_categories extends Secure_Controller
 			echo json_encode ([
 				'success' => FALSE,
 				'message' => lang('Tax_categories.error_adding_updating') . ' ' . $tax_category_data['tax_category'],
-				'id' => -1	//TODO: Need to replace -1 with constant
+				'id' => NEW_ENTRY
 			]);
 		}
 	}
 
-	public function delete(): void
+	public function postDelete(): void
 	{
 		$tax_categories_to_delete = $this->request->getPost('ids', FILTER_SANITIZE_NUMBER_INT);
 
diff --git a/app/Controllers/Tax_codes.php b/app/Controllers/Tax_codes.php
index 5249248f2..e6997483c 100644
--- a/app/Controllers/Tax_codes.php
+++ b/app/Controllers/Tax_codes.php
@@ -61,7 +61,7 @@ class Tax_codes extends Secure_Controller
 		echo json_encode($data_row);
 	}
 
-	public function getView(int $tax_code_id = -1): void	//TODO: Need to replace -1 with constant
+	public function getView(int $tax_code_id = NEW_ENTRY): void
 	{
 		$data['tax_code_info'] = $this->tax_code->get_info($tax_code_id);
 
@@ -69,7 +69,7 @@ class Tax_codes extends Secure_Controller
 	}
 
 
-	public function save(int $tax_code_id = -1): void		//TODO: Need to replace -1 with constant
+	public function postSave(int $tax_code_id = NEW_ENTRY): void
 	{
 		$tax_code_data = [
 			'tax_code' => $this->request->getPost('tax_code', FILTER_SANITIZE_STRING),
@@ -80,7 +80,7 @@ class Tax_codes extends Secure_Controller
 
 		if($this->tax_code->save($tax_code_data))
 		{
-			if($tax_code_id == -1)	//TODO: Need to replace -1 with constant
+			if($tax_code_id == NEW_ENTRY)
 			{
 				echo json_encode ([
 					'success' => TRUE,
@@ -102,12 +102,12 @@ class Tax_codes extends Secure_Controller
 			echo json_encode ([
 				'success' => FALSE,
 				'message' => lang('Tax_codes.error_adding_updating') . ' ' . $tax_code_data['tax_code_id'],
-				'id' => -1
+				'id' => NEW_ENTRY
 			]);
 		}
 	}
 
-	public function delete(): void
+	public function postDelete(): void
 	{
 		$tax_codes_to_delete = $this->request->getPost('ids', FILTER_SANITIZE_NUMBER_INT);
 
diff --git a/app/Controllers/Tax_jurisdictions.php b/app/Controllers/Tax_jurisdictions.php
index 55bec76ad..fdb57141f 100644
--- a/app/Controllers/Tax_jurisdictions.php
+++ b/app/Controllers/Tax_jurisdictions.php
@@ -56,7 +56,7 @@ class Tax_jurisdictions extends Secure_Controller
 		echo json_encode($data_row);
 	}
 
-	public function getView(int $tax_jurisdiction_id = -1): void	//TODO: Replace -1 with constant
+	public function getView(int $tax_jurisdiction_id = NEW_ENTRY): void
 	{
 		$data['tax_jurisdiction_info'] = $this->tax_jurisdiction->get_info($tax_jurisdiction_id);
 
@@ -64,7 +64,7 @@ class Tax_jurisdictions extends Secure_Controller
 	}
 
 
-	public function save(int $jurisdiction_id = -1): void	//TODO: Replace -1 with constant
+	public function postSave(int $jurisdiction_id = NEW_ENTRY): void
 	{
 		$tax_jurisdiction_data = [
 			'jurisdiction_name' => $this->request->getPost('jurisdiction_name', FILTER_SANITIZE_STRING),
@@ -73,7 +73,7 @@ class Tax_jurisdictions extends Secure_Controller
 
 		if($this->tax_jurisdiction->save_value($tax_jurisdiction_data))
 		{
-			if($jurisdiction_id == -1)	//TODO: Replace -1 with constant
+			if($jurisdiction_id == NEW_ENTRY)
 			{
 				echo json_encode ([
 					'success' => TRUE,
@@ -95,12 +95,12 @@ class Tax_jurisdictions extends Secure_Controller
 			echo json_encode ([
 				'success' => FALSE,
 				'message' => lang('Tax_jurisdictions.error_adding_updating') . ' ' . $tax_jurisdiction_data['jurisdiction_name'],
-				'id' => -1
+				'id' => NEW_ENTRY
 			]);
 		}
 	}
 
-	public function delete(): void
+	public function postDelete(): void
 	{
 		$tax_jurisdictions_to_delete = $this->request->getPost('ids', FILTER_SANITIZE_NUMBER_INT);
 
diff --git a/app/Controllers/Taxes.php b/app/Controllers/Taxes.php
index 53023b86a..b080c13d4 100644
--- a/app/Controllers/Taxes.php
+++ b/app/Controllers/Taxes.php
@@ -126,7 +126,7 @@ class Taxes extends Secure_Controller
 		echo json_encode($data_row);
 	}
 
-	public function getView_tax_codes(int $tax_code = -1): void	//TODO: Replace -1 with constant
+	public function getView_tax_codes(int $tax_code = NEW_ENTRY): void
 	{
 		$tax_code_info = $this->tax->get_info($tax_code);
 
@@ -147,7 +147,7 @@ class Taxes extends Secure_Controller
 		$data['rounding_options'] = rounding_mode::get_rounding_options();
 		$data['html_rounding_options'] = $this->get_html_rounding_options();
 
-		if($tax_code == -1)	//TODO: Replace -1 with constant
+		if($tax_code == NEW_ENTRY)
 		{//TODO: Duplicated code
 			$data['tax_code'] = '';
 			$data['tax_code_name'] = '';
@@ -194,7 +194,7 @@ class Taxes extends Secure_Controller
 	}
 
 
-	public function getView(int $tax_rate_id = -1): void	//TODO: Replace -1 with constant
+	public function getView(int $tax_rate_id = NEW_ENTRY): void
 	{
 		$tax_rate_info = $this->tax->get_info($tax_rate_id);
 
@@ -205,7 +205,7 @@ class Taxes extends Secure_Controller
 		$data['tax_category_options'] = $this->tax_lib->get_tax_category_options();
 		$data['tax_jurisdiction_options'] = $this->tax_lib->get_tax_jurisdiction_options();
 
-		if($tax_rate_id == -1)	//TODO: Replace -1 with constant
+		if($tax_rate_id == NEW_ENTRY)
 		{
 			$data['rate_tax_code_id'] = $this->config['default_tax_code'];
 			$data['rate_tax_category_id'] = $this->config['default_tax_category'];
@@ -226,7 +226,7 @@ class Taxes extends Secure_Controller
 		echo view('taxes/tax_rates_form', $data);
 	}
 
-	public function getView_tax_categories(int $tax_code = -1): void	//TODO: Replace -1 with constant	//TODO: This appears to be called no where in the code.
+	public function getView_tax_categories(int $tax_code = NEW_ENTRY): void	//TODO: This appears to be called no where in the code.
 	{
 		$tax_code_info = $this->tax->get_info($tax_code);	//TODO: Duplicated Code
 
@@ -247,7 +247,7 @@ class Taxes extends Secure_Controller
 			$data['default_tax_type'] = Tax_lib::TAX_TYPE_EXCLUDED;
 		}
 
-		if($tax_code == -1)	//TODO: Replace -1 with constant
+		if($tax_code == NEW_ENTRY)
 		{
 			$data['tax_code'] = '';
 			$data['tax_code_name'] = '';
@@ -293,7 +293,7 @@ class Taxes extends Secure_Controller
 		echo view('taxes/tax_category_form', $data);
 	}
 
-	public function getView_tax_jurisdictions(int $tax_code = -1): void	//TODO: Replace -1 with constant	//TODO: This appears to be called no where in the code.
+	public function getView_tax_jurisdictions(int $tax_code = NEW_ENTRY): void //TODO: This appears to be called no where in the code.
 	{
 		$tax_code_info = $this->tax->get_info($tax_code);	//TODO: Duplicated code
 
@@ -314,7 +314,7 @@ class Taxes extends Secure_Controller
 			$data['default_tax_type'] = Tax_lib::TAX_TYPE_EXCLUDED;
 		}
 
-		if($tax_code == -1)	//TODO: Replace -1 with constant
+		if($tax_code == NEW_ENTRY)
 		{
 			$data['tax_code'] = '';
 			$data['tax_code_name'] = '';
@@ -365,7 +365,7 @@ class Taxes extends Secure_Controller
 		return rounding_mode::get_html_rounding_options();
 	}
 
-	public function save(int $tax_rate_id = -1): void	//TODO: Replace -1 with constant
+	public function postSave(int $tax_rate_id = NEW_ENTRY): void
 	{
 		$tax_category_id = $this->request->getPost('rate_tax_category_id', FILTER_SANITIZE_NUMBER_INT);
 		$tax_rate = parse_tax($this->request->getPost('tax_rate', FILTER_SANITIZE_NUMBER_FLOAT, FILTER_FLAG_ALLOW_FRACTION));
@@ -385,7 +385,7 @@ class Taxes extends Secure_Controller
 
 		if($this->tax->save_value($tax_rate_data, $tax_rate_id))
 		{
-			if($tax_rate_id == -1)	//TODO: Replace -1 with constant
+			if($tax_rate_id == NEW_ENTRY)
 			{//TODO: this needs to be replaced with ternary notation
 				echo json_encode (['success' => TRUE, 'message' => lang('Taxes.tax_rate_successfully_added')]);
 			}
@@ -400,7 +400,7 @@ class Taxes extends Secure_Controller
 		}
 	}
 
-	public function delete(): void
+	public function postDelete(): void
 	{
 		$tax_codes_to_delete = $this->request->getPost('ids', FILTER_SANITIZE_NUMBER_INT);