1 files changed, 18 insertions, 1 deletions
diff --git a/mdoc.3 b/mdoc.3
index fe09e890..7bddf115 100644
--- a/mdoc.3
+++ b/mdoc.3
@@ -89,7 +89,9 @@ This section further defines the
 .Sx Functions 
 and
 .Sx Variables
-available to programmers.  The last sub-section,
+available to programmers.  Following that,
+.Sx Character Encoding
+describes input format.  Lastly, 
 .Sx Abstract Syntax Tree ,
 documents the output tree.
 .\" SUBSECTION
@@ -174,6 +176,21 @@ An array of string-ified token names.
 An array of string-ified token argument names.
 .El
 .\" SUBSECTION
+.Ss Character Encoding
+The
+.Xr mdoc 3
+library accepts only printable ASCII characters as defined by
+.Xr isprint 3 .
+Non-ASCII character sequences are escaped with an escape character 
+.Sq \\
+and followed by either an open-parenthesis 
+.Sq \&(
+for two-character sequences; an open-bracket
+.Sq \&[
+for n-character sequences (terminated at a close-bracket
+.Sq \&] ) ;
+or one of a small set of single characters for other escapes.
+.\" SUBSECTION
 .Ss Abstract Syntax Tree
 The 
 .Nm