--- usr.bin/awk/awk.1.orig      2017-09-14 06:48:23.169390000 +0100
+++ usr.bin/awk/awk.1   2018-02-22 10:22:11.160251000 +0000
@@ -76,7 +76,7 @@
 .Nm
 to dump core on fatal errors.
 .It Fl F Ar fs
-Define the input field separator to be the regular expression
+Define the input field separator to be the single character literal, or regular expression
 .Ar fs .
 .It Fl f Ar progfile
 Read program code from the specified file
@@ -131,7 +131,7 @@
 This is convenient when working with multi-line records.
 .Pp
 An input line is normally made up of fields separated by whitespace,
-or by the regular expression
+a single character literal, or by the regular expression
 .Va FS .
 The fields are denoted
 .Va $1 , $2 , ... ,
@@ -162,6 +162,8 @@
 .Fl F
 option with a value of
 .Sq [t] .
+Any other single character separator is treated as a literal.
+2 characters or more are treated as a regular expression.
 .Pp
 A pattern-action statement has the form
 .Pp