what is the arrow called?

[Ralf Mardorf]

On Tue, 11 Nov 2014 11:26:44 -0800
ToddAndMargo <ToddAndMargo at zoho.com> wrote:
> On an Xfce windows, in the upper left of the decorations strip,
> there is an up/down arrow that shrinks the window to the
> decoration strip or expands it back to its original shape.
> 
> What is this arrow called?  

I'm neither running a Xfce4 session now, nor is my Xfce4 set up in the
same way as yours is. At the moment I'm logged in an openbox session.

I don't have an icon in the decoration that provides this, but if I
right click at the decoration bar I get a menu and for openbox it's
called "Roll up/down".

Likely you can right click at the decoration bar for Xfce4 too and you
likely will see what it's called for Xfce4.

Hth,
Ralf