style checks related to .Er; inspired by mdoclint(1)

1 files changed, 30 insertions, 0 deletions

diff --git a/mandoc.1 b/mandoc.1
index 128667b1..69be40ac 100644
--- a/mandoc.1
+++ b/mandoc.1
@@ -75,6 +75,11 @@ and for the
 .Xr man 7
 .Ic \&TH
 macro.
+This can also be used to perform style checks according to the
+conventions of one operating system while running on a different
+operating system; see
+.Sx Style messages
+for details.
 .It Fl K Ar encoding
 Specify the input encoding.
 The supported
@@ -743,6 +748,15 @@ option or
 .Fl T Cm lint
 output mode.
 .Ss Style messages
+As indicated below, some style checks are only performed if a
+specific operating system name occurs in the arguments of the
+.Ic \&Os
+macro, of the
+.Fl Ios
+command line option, or, if neither are present, in the return value
+of the
+.Xr uname 3
+function.
 .Bl -ohang
 .It Sy "useless macro"
 .Pq mdoc
@@ -763,6 +777,22 @@ macro that could be represented using
 .Ic \&Fx ,
 or
 .Ic \&Dx .
+.It Sy "errnos out of order"
+.Pq mdoc, Nx
+The
+.Ic \&Er
+items in a
+.Ic \&Bl
+list are not in alphabetical order.
+.It Sy "duplicate errno"
+.Pq mdoc, Nx
+A
+.Ic \&Bl
+list contains two consecutive
+.Ic \&It
+entries describing the same
+.Ic \&Er
+number.
 .It Sy "description line ends with a full stop"
 .Pq mdoc
 Do not use punctuation at the end of an