Display zoom key shortcut

[Arnaud bourree]

Hello,

I discover a key shortcut for display zoom: on my French keyboard,
<META><+> zoom in the full screen on my both display.
The <+> key is located on my French keyboard on the left of the <back
space key>.
That is nice effect, but I don't how to zoom out nor how to restore
default size.
And I don't find where that is configured (Stand keyborad shortcut
defined <CRTL><+> and <CTRL><-> which doesn't have effect on the full
screen)

Does anyone knows how to disabled that or how to zoom out?

Regards,

Arnaud.