[Zope] action modifier adds calling method to URL?

[Milos Prudek]

I have a method "run" that is called from method "display" on
/presley/elvis folder. When using simple form as follows...

<form action="run">
  <input type="submit" name="submit" value="Run!">
</form>

... it goes to a correct URL: /presley/elvis/run
... and URL0 is /presley/elvis/run

However, I'd like to use :action modifier, as follows:

<form action="">
  <input type="submit" name="run:action" value="Run!">
  <input type="submit" name="set:action" value="Set!>
</form>

This works fine, but it goes to: 

/presley/elvis/display/run or  /presley/elvis/display/set.

and URL0 is also /presley/elvis/display/run or 
/presley/elvis/display/set.

This '/display/' disturbs logic of my program (things like PARENTS).

Is this standard behaviour, or a Zope fault? 

If it's standard, what is the advantage of this behaviour?

--
Milos Prudek