Alrigh so when yahoo introduced the Connection filtering mode to make it easy to read messages from the connections i found it a bit limited because clearly not everyone in my adress book is a Connection.
So than they introduced the Contact filtering in order to highlight messages from people in my address book. i have to say I like the idea but...
here is the thing:
The filter work very well when people from my adress book send me an email to my yahoo address.
but see i use a custom domain on Google apps and have all some email automatically forwarded to my Yahoo! Mail account. Even if the sender of the email is in my Yahoo address book it will not get filtered.
So basically the Contact option filter :
messages from people in the Y! address book ONLY IF those messages were sent to the Yahoo email address at first