This is a new feature available only from version 3+. It allows you to create an “alias” for a link or part of the link.
View tutorial here
You can create “alias” for a part of the link, but it must be a “whole part”, see this example:
site.com/abc-category-c-12/audi-2008-p-29
“abc-category-c-12” and “audi-2008-p-29” are “whole parts”, while “abc-category” and “audi-2008” are not.
“abc-category-c-12/audi-2008-p-29” is also considered a “whole part”, so you can create alias for this as well.
With the Auto Alias Feature added in 3.6.0 RC2, SSU makes it much more easier for you who want to remove all identifiers (i.e: -p-19) from all the links.
Permanent link: As of version 3.6+, a new feature called “permanent” alias was added. With Auto Alias turned on, SSU will always recalculate the alias in case you change product/category names, or in case you want to use an alias that is different from the name. (btw, you always have to reset SSU cache first in these cases).
This behavior is not always welcome in certain cases, so you can set the aliases you don't want to be automatically changed to “permanent”
Even though SSU DOES use 301 redirection for you, it will take Search Engines a while to drop the old links. So in a short amount of time it may affect your Search Engine Ranking. If you have been using SSU for a while with the old link style, and you are happy with it, you should NOT turn on this feature. Read on to see the side-effects of removing identifiers from your links.
Example:
http://yoursite.com/cars-toyota-c-15_24/accord-p-19
If the customer for whatever reason type in the wrong name for either the product or category or both:
http://yoursite.com/carsss-toyotaaa-c-15_24/accordasda-p-19
As long as the id(s) are correct, SSU will redirect them to the correct link.
http://yoursite.com/cars/toyota/accord
Look nice? Yes. But remember any SSU will not be able to redirect wrong links like this:
Example: if you have a product named “new car”, you use ”-” as the delimiter (set via SSU admin) and you have a define page named new-car, then SSU will not generate a pretty alias for this product name for the obvious reason.
What you can do in this case is: you can go into the Alias Manager and manually add the alias for this product (and you must use an alias that is different from your define page)
A very good example here: you have 2 product names: “car a” and “car b”, note these 2 products don't even have the same name. But, if in your SSU setting you set it to cut off words shorter than 2 characters for example, then after being parsed they will have the same name: “car”. Obviously, SSU will assign the “car” alias to one of the 2, while leaving the other with the “old style” name (i.e: car-p-3).
What you can do in this case is: you can go into the Alias Manager and manually add the alias for this product.