Read only if makes a field read only if a condition is met. 

Supports the following conditions: Equal, Not equal, Less than, Less than or equal, Greater than, Greater than or equal, Is empty, and Is not empty.

Also supports Compound logic. Logical operators are evaluated from left to right, and in the following order:

1. Evaluate all less than and greater than, next
2. Evaluate all equals to, next
3. Evaluate all logical AND, next
4. Evaluate all logical OR, next.