Language string for Facebook sharing

Further to:

http://stackideas.com/forums/es-share-to-facebook-title

Seems to be another misunderstanding. What I'm after is the Language String which makes up the title when a link share post is shared to Facebook.

Please see original forum post for screenshots and details...

It is the piece of text which says:
"........... shared a link"

In this case:
"OpgroeiGids Redactie heeft een link gedeeld"

This comes from a language string and that is what I'm trying to get info on...