"Valid values " are values that a channel requires in certain fields. You have to send the imposed value for the field for the channel to take note of it.
In most cases these valid values are essential for the creation of your products on the channel.
You will find the imposed valid values in "Attributes Matching ". Depending on the situation they can be:
- directly integrated: choose the value from the drop down menu
- in the field definition: read it very carefully