zz## OpenType features

André G. Isaak

I’ve noticed that a fairly large number of non-Latin fonts contain feature tags of the form 'zz##', but these are not listed in the OpenType feature registry. I gather these have something to do with localization (based on cases I’ve analyzed), but I have no idea what causes these features to be activated. Can anyone point me to a source of information on what these features are used for?

Erwin Denissen

We consider those as production tables for VOLT which should not end up in release versions of fonts. If this is a false assumption let us know.

John Hudson

Yes, these are internal VOLT source features which are stripped from the font when using the Ship Font option in VOLT.

André G. Isaak

Ah. OK. So I guess a lot of people are simply forgetting to strip these and I shouldn't worry about them.

Erwin Denissen

Yes, some people forget it. See for example Calibri type face version 6.23.

Ashfaq Niazi

André G. Isaak said:

I’ve noticed that a fairly large number of non-Latin fonts contain feature tags of the form 'zz##', 

Not in non-Latin also I found in my Arabic fonts. I found many zz## visible in Fontlab source without Shipping the font, but when I simply ship the font from VOLT, these zz## are finished from FontLab source Code and It only shows features which I used in VOLT program.

Erwin Denissen said:

Yes, some people forget it. See for example Calibri type face version 6.23.

Is there a special technique to stip them from font, or any post I can study. I simply shipped font from VOLT and found no zz##, which was there before shipping. 

Erwin Denissen

As John Hudson indicated, using the Ship Font option in VOLT will ensure those features are not included.

We obviously use FontCreator to edit OpenType layout features; it even allows you to import fonts that contain VOLT data.