Naming your own link?

I used to be able to do this, but I forgot.

If you want to put in a link, the software names it for you. For instance, here's a link to a forum about foam:
Polyfoam/reticulated foam

Now if I wanted the link to appear as "Foam Stuff" instead of Polyfoam/reticulated foam", there used to be a way to do it.

Does anyone know?

Thanks. :)