Are there any issues when using IBAction when it is not actually called from a user's action?

If you have an action like

-(IBAction)sayHello:(id)sender;

You can call it from within your class like:

[self sayHello:@"x"]

The @"x" doesn't do anything, it just fills in for the sender.

You can actually create an IBAction method without (id)sender

-(IBAction)sayHello;

and call it from both user's actions and from within the code, but then you won't get any useful sender info from the interface. What's the 'correct' way of filling in for the sender, when calling from the code? And can you create sender info to send when it's called from within the code?

Just trying to figure it out.