In late 2011, Google updated the Google Product Search (formerly known as Froogle) feed format to make certain new parameters required values. More information about this can be found on Google's official merchant blog:
Over the years, Google has changed the spec and format of the feed almost as often as they've changed the name (Froogle, Googlebase, etc.). It has become somewhat of a moving target.
The latest update complicates things further as whether certain parameters are required or not depends on the country you are based in, as well as the type of products you sell. To try to make Kartris as flexible as possible in this respect, we've handled the new requirements by adding a new attribute type to Kartris.
Auto-filled Google Product Search parameters
Firstly, a recap on the parameters which Kartris puts in the feed automatically:
The following attribute can be selected from a menu at the time of feed generation:
Custom/New Google Product Search parameters
From v1.3005 onwars, Kartris has the capability to add extra values to the feed for each product using the product attributes system.
First, you will need to go to Products > Product Attributes. Click to add a new attribute. Name the
new attribute and select it as a Google Feed Special attribute, as below:
Now when you edit a product, the new parameter will show on the 'attributes' tab. You can select it and add a value for it. Where the value of the attribute is not blank, Kartris will export this in the Google Product Search feed.
Attributes are set at product level. So while each version under a product can have its own auto-filled parameters (such as g:price, g:id, etc.), it will share the custom parameters with the other versions of the product. If versions under a product need to have different custom parameters for Google, then they will need to be spun out as separate products, rather than versions of the same product.