How to prevent duplicated URLs coused by multiple ItemIDs
ItemID is one of the most important and problematic part of Joomla! and SEF, check out the OSTraining tutorial for more infoabout what is ItemID http://bit.ly/chjojc
1. One article/category pointed in 2 different menus
2. Some modules, not coded well, do not add the correct ItemID to non-SEF links, they add the ItemID of active page to links.
In this article we'll show you how to solve the #1 problem with AceSEF.
As per result, SEF components will generate 2 different URLs for these menu items:

So a second URL for that article won't be created.
NOTE: It's recommended to lock that SEF URL from AceSEF=>URLs page because it's ID is stored in menu item.
1. Introduction
There are 2 main reasons of creating duplicated URLs from multiple ItemIDs:1. One article/category pointed in 2 different menus
2. Some modules, not coded well, do not add the correct ItemID to non-SEF links, they add the ItemID of active page to links.
In this article we'll show you how to solve the #1 problem with AceSEF.
2. Case study
As you can see from the following image, on our live site we use 2 different menus to show the company's articles, Main Menu and Company Menu.
As per result, SEF components will generate 2 different URLs for these menu items:

3. Solution
Since AceSEF 1.5.4, we've implemented a smooth solution for this problem. You will have the oppurtunity to add an AceSEF URL to any menu item:

So a second URL for that article won't be created.
NOTE: It's recommended to lock that SEF URL from AceSEF=>URLs page because it's ID is stored in menu item.