Thanks for the quick follow-up, Reed!

At 2020-01-25T13:13:44-0600, reed@reedmedia.net wrote:
> On Sun, 26 Jan 2020, G. Branden Robinson wrote:
> 
> > I'm inlining my findings in rendered and source form below, but
> > there's one feature I haven't been able to sort out--where did .SB
> > (small bold) come from?  The oldest groff release I can find online
> > is 1.02 (June 1991), and .SB is already there, but I can't find it
> > anywhere else.  Is it a GNUism?  Did it perhaps appear in a
> > proprietary Unix first?
> 
> I see .SB used in the 
> C Manual - Language
> Edited by R.P.A. Collinson
> Document No: DOC/UNIX.K3.10/1
> and UKC IO Library docs also from Collinson at Univ. of Kent.
> as found in the usenix-78-uk1 tape.
> Maybe that is uk1.tar at 
> https://www.tuhs.org/Archive/Applications/Spencer_Tapes/

There's definitely an .SB macro used in that and a few other *roff
documents in the uk1 archive, all of which have filenames ending in
".n".

They're not laid out like man pages, there's no tmac.n file in the
archive, and the macros used don't seem to come from Matt Bishop's News
macro package, also named tmac.n.

Given the absence of the macro package source it's hard to say what the
semantics of these documents' ".SB" might be.  They appear to be used as
section headings, but C function prototypes are used with them as well.
But since a C library is being documented alongside the language, maybe
that's not too surprising.

> I also see a SB Stymie Bold font in v7 troff.

That's a different namespace.  Something it took me an embarrassingly
long to figure out was the ridiculously terse naming convention of *roff
font description files.

The "foundry" name gets the first letter, and after that you get "R" for
roman, "B" for bold, "I" for italic, "BI" for bold italic, and "S" for a
"special" font (symbols for math typesetting or dingbats).  Bold and
italics didn't apply to special fonts.

So, if your system has Helvetica you'll have files called:
	HR
	HB
	HI
	HBI

If my guess is right, alongside Stymie Bold you'll see SR, SI, and
possibly SBI as well.

Regards,
Branden