Are empty DSIG tables in a font useless?

Richard Fink

Years ago, I asked Thomas Phinney why I was seeing an "Opentype" icon - that is, an icon with an "0" on it - instead of the usual TrueType icon being displayed in Windows XP for TrueType fonts. He told me that, for some reason, if there is a DSIG table, Windows displays an OpenType icon even if it's a TrueType font. Why, he did not know.  A quirk.

Recently, I've been working with some fonts that have empty DSIG tables in them (which I've seen before, now and then), and in asking around was told that some rasterizers in Windows (Office?), will handle a font differently if it sees that DSIG table than if it didn't.

Is that true?  Is that the typographic equivalent of an urban legend? What?

Does an empty DSIG table in a TrueType font, or in a cubic OT font, for that matter, play any part in how Windows deals with the font?

LeMo aka PatternMan aka Frank E Blokland

Hi Richard,

The DSIG table distinguishes the TTF-flavored OpenType fonts from plain TTF’s and activates the OT Layout features in MS Office applications. This was discussed a couple of years ago here:

http://typedrawers.com/discussion/192/making-ot-ttf-layout-features-work-in-ms-word-2010

Richard Fink

Thank you Frank. Obviously I didn't do my preliminary Googling. My bad.  And thanks to Butterick for the original post.  OK, I guess I'll have to keep a file with a dummy DSIG table in it to merge into fonts using a tool like DTL OTMaster.