<p>I have a property called "IsSecureConnection" that is part of my object's interface.  This makes sense for most implementations of the interface, however, in some implementations I would like to make the property ReadOnly.  </p>

<p>Should I omit this property from the object's interface even though it is required by all of the implementations (though  slightly different on occasion)?</p>

<p>Thanks!</p>

Just add the getter in the interface.
```
```
public interface Foo{
  bool MyMinimallyReadOnlyPropertyThatCanAlsoBeReadWrite {get;}
}
```
```
Interfaces specify the minimum an object must implement; it doesn't say what an object cannot do.  For that, you need to look into creating base classes.