UPDATE: Added new required fields to Google base feed

Changed “Google Base” to “Google Product Search” in our menu and settings screen. Updated the instruction text to be relevant to the current process.

Added new required fields to Google base feed:

Required for all products: gtin, availability, google_product_category
Required for apparel: gender, age_group
Required for apparel and variant products: color, size
Required for apparel (if applicable): material, pattern

GTIN will be pulled from the new GTIN field on products:

Availability is mapped as follows:
“in stock” – any product status that isn’t unavailable or backorder
“available for order” – product status is backorder and stock is <= 0
“out of stock” – unavailable product statuses
“preorder” – not supported for automatic mapping, can be set with custom field override

Availability can be overridden at the product level by adding a custom field called “Availability”.

Products with variant inventory will be split into separate items based on the available variations. All applicable fields will be overridden with information from the variant inventory record. Assuming the variant groups for the item are named Color, Size, Material, and Pattern, those attributes will be automatically mapped from the variant inventory’s variant names. They can also be set at the product level with custom fields of the same name for non-variant apparel.

The remaining attributes are mapped from the following custom fields:
GoogleProductCategory
Gender
AgeGroup

See http://www.google.com/support/merchants/bin/answer.py?answer=188494 for the full feed specification.