diff --git a/book-summary-macros.ms b/book-summary-macros.ms
new file mode 100644
index 0000000..c612563
--- /dev/null
+++ b/book-summary-macros.ms
@@ -0,0 +1,8 @@
+.de SUMMARIZED_BY
+.AUTHOR
+.ft CW
+summarized by
+.ft
+\\$*
+.
+..