> Pablo Rodriguez <mailto:oinos@gmx.es>
> 19. März 2017 um 22:08via Postbox 
> <https://www.postbox-inc.com/?utm_source=email&utm_medium=sumlink&utm_campaign=reach>
>
> Yes, this might work, but I’m afraid I need to disable other default
> features such as ligatures (not only liga, but TeX ligatures).
>
> I had this problem typesetting XML sources and I didn’t know how to
> disable the other features.
The default setting is “feature=default” and to get expansion/protrusion 
additional
to kerning etc. you have two options:

1. Add them to the default feature with 
\definefontfeature[default][default][expansion=quality,protrusion=quality]

2. Set multiple feature with 
\definefontfamily[...][...][...][features={default,quality}]

You can use the second method when you want only expansion/protrusion. 
When you
set only “features=quality” kerning isn’t enabled because the default 
features aren’t
applied to your font.

Wolfgang