Google Base lists out all attributes defined by them here - [base.google.com...]

I noticed that the most of the attributes had either "Acceptable" values or "Appropriate" values outlined. What is the difference between these 2 types of values? Is one more stringent over the other?

For example:
Attribute name - gender
Format: Acceptable values are: male, M, female, or F.

Attribute name - listing_status
Format: Appropriate values include: active, offer, contract, closed, and withdrawn.