title: Asp.Net Custom Control design time question
body: <p>I'm developing a set of custom controls, one of them are the "parent", any others must be added inside an ITemplate property of this parent. </p>
  
  <p>But in the page, at design time, I can see, by intellisense, the other controls at page level, and I can theorically add them everywhere.</p>
  
  <p>I want to emulate the behaviour of the asp:Table and the asp:TableRow, you can't directly add an asp:TableRow outside an asp:Table...</p>
  
  <p>Is there a way to reach this?
  Many thanks!</p>
  
  <p><strong>edit</strong>: I've partially solved with the KP suggestion, but if you read at the comment it's not the "real" way to do this (I think). 
  No one knows how to do that? :(</p>