libroff now intelligently throws away `am', `ami', `am1', `de', `dei',

and `de1'.  This is also documented in roff.7.

1 files changed, 51 insertions, 3 deletions

diff --git a/roff.7 b/roff.7
index 10b319a5..2d3ae9cb 100644
--- a/roff.7
+++ b/roff.7
@@ -65,9 +65,56 @@ Thus, the following are equivalent:
 .Sh REFERENCE
 This section is a canonical reference of all macros, arranged
 alphabetically.
+.Ss \&am
+The syntax of this macro is the same as that of
+.Sx \&ig ,
+except that a leading argument must be specified.
+It is ignored, as are its children.
+.Ss \&ami
+The syntax of this macro is the same as that of
+.Sx \&ig ,
+except that a leading argument must be specified.
+It is ignored, as are its children.
+.Ss \&am1
+The syntax of this macro is the same as that of
+.Sx \&ig ,
+except that a leading argument must be specified.
+It is ignored, as are its children.
+.Ss \&de
+The syntax of this macro is the same as that of
+.Sx \&ig ,
+except that a leading argument must be specified.
+It is ignored, as are its children.
+.Ss \&dei
+The syntax of this macro is the same as that of
+.Sx \&ig ,
+except that a leading argument must be specified.
+It is ignored, as are its children.
+.Ss \&de1
+The syntax of this macro is the same as that of
+.Sx \&ig ,
+except that a leading argument must be specified.
+It is ignored, as are its children.
 .Ss \&if
-Begins a conditional.
-Has the following syntax:
+Begins a conditional that always evaluates to false.
+If a conditional is false, its children are not processed, but are
+syntactically interpreted to preserve the integrity of the input
+document.
+Thus,
+.Pp
+.D1 \&.if t \e .ig
+.Pp
+will discard the
+.Sq \&.ig ,
+which may lead to interesting results, but
+.Pp
+.D1 \&.if t \e .if t \e{\e
+.Pp
+will continue to syntactically interpret to the block close of the final
+conditional.
+Sub-conditionals, in this case, obviously inherit the truth value of
+the parent.
+This macro has the following syntax:
 .Pp
 .Bd -literal -offset indent -compact
 \&.if COND \e{\e
@@ -88,7 +135,8 @@ BODY...
 BODY
 .Ed
 .Pp
-COND is a conditional (TODO: document).
+COND is a conditional (for the time being, this always evaluates to
+false).
 .Pp
 If the BODY section is begun by an escaped brace
 .Sq \e{ ,