smartlist question

Assuming you have a custom field called "Product Edition" you would just use a filter to say "Product Edition IS NOT A or B"

The little green plus button will let you add multiple values to the filter and they act as "OR" when grouped together

Thanks Matt.  But the issue is that I would like to exclude the group of customers who are using both product edition a AND b. Not "or".  How would I do this? 

It'd be easier to tell you if you told us what your fields are set up as... so I'll just make an assumption that you have two custom fields: Product Edition A and Production Edition B and each are checkboxes, with either true or false values.

So in your smart list, you'd add each field to the list of filters and set each to "is TRUE"

By default, the filter logic of a smart list is set to "ALL" so that's all you'd need to do for it to list everyone that you want to exclude.

Now, when you create your email program (I assume that's what you're doing), add a filter for "Member of Smart List IS NOT" and use the exclusion list you created previously.