[HFC3]

How do you code a "not equal" condition in a search filter?

Help says any Python expression is accepted, but I can't get != to work;
{field}!={value}
{field}:!={value}
{field}:!{value}

All return no results.

Also, how do you code an OR? .{val}.{val} works for an itemized list field as an AND, but how would I code an OR?

And, how do you code an AND or an OR where the blank value is also OK?

Thanks!