I got this from mdoc(7),

The table:

      String    Nroff    Troff
      <=        <=       ≤
      >=        >=       ≥

was produced by:

.Bl -column -offset indent ".Sy String" ".Sy Nroff" ".Sy Troff"
.It Sy String Ta Sy Nroff Ta Sy Troff
.It Li <= Ta <= Ta \*(<=
.It Li >= Ta >= Ta \*(>=
.El

There are existing man pages with both ".Sy (e.g. share/man/man1/builtin.1) and "Sy, so either way we should do a pass to make them consistent.

In D7261#150976, @emaste wrote:

There are existing man pages with both ".Sy (e.g. share/man/man1/builtin.1) and "Sy, so either way we should do a pass to make them consistent.

GNU groff with our mdoc is unhappy:

$ troff -Tdvi -mdoc share/man/man7/arch.7 | grodvi >|~/tmp/arch.7.dvi
Usage: .Sy symbolic_text ... (#50)
Usage: .Sy symbolic_text ... (#69)
$

I have no objection.

@wblock, should mdoc.7 be updated to remove the . from the example I pasted?

In D7261#151132, @emaste wrote:

@wblock, should mdoc.7 be updated to remove the . from the example I pasted?

As far as I know, mdoc(7) in FreeBSD 10 is the old one, and mdoc(7) in FreeBSD 11 and later is the new one from mandoc. I don't know if they contain the same example, or what is going on with the versions, really.

The example looks correct to me. It's just that mdoc understands macros without the dot in some contexts.

In D7261#150976, @emaste wrote:

There are existing man pages with both ".Sy (e.g. share/man/man1/builtin.1) and "Sy, so either way we should do a pass to make them consistent.

I do not see any Sy in builtin.1, but our style is to only have the '.' in column 1.

It's just that mdoc understands macros without the dot in some contexts.

It stays in macro context until the end of the line.

I mdoc format as properly stated in the mdoc(7) manpage in head

macros does not start with a '.'
the lines started with a '.' are special:

In an mdoc document, lines beginning with the control character ‘.’ are called “macro lines”.  The first word is the macro.