1 files changed, 6 insertions, 0 deletions
diff --git a/txr.1 b/txr.1
index 86b30e8d..0c86dd5d 100644
--- a/txr.1
+++ b/txr.1
@@ -1315,6 +1315,12 @@ which translates to a combination of @(cases) and @(require)
 Multiple clauses are applied to the same input. The one whose effect persists
 is the one which maximizes or minimizes the length of a particular variable.
 
+.IP @(empty)
+The @(empty) directive matches the empty string. It is useful in certain
+situations, such as expressing an empty match in a directive that doesn't
+accept an empty clause. The @(empty) syntax has another meaning in
+@(output) clauses, in conjunctio with @(repeat).
+
 .IP "@(define NAME ( ARGUMENTS ...))"
 Introduces a function. Functions are discussed in the FUNCTIONS section below.