[news.eclipse.modeling.gmf] Purpose of Type Link Model Facet?

[conorgaff@xxxxxxxxxxx (Gaff)]

Hi all,

I recently set a canvas link from a node so that when there's a double 
click on the node a second canvas opens up, as described in the thread:

http://dev.eclipse.org/newslists/news.eclipse.modeling.gmf/msg02691.html
(thanks to Alex Shatalin)

When I was building the gmfgen model, there was one error that appeared 
that I needed to fix, I had to set the Target Meta Feature of the Type 
Link Model Facet.

I had a guess at it and it all seems to be working fine. But I was just 
wondering what the purpose of this was?

Thanks,

Gaff