diff --git a/Doc/lib/libtarfile.tex b/Doc/lib/libtarfile.tex
index 5f277da..1a53a27 100644
--- a/Doc/lib/libtarfile.tex
+++ b/Doc/lib/libtarfile.tex
@@ -36,7 +36,8 @@
     \lineii{'r:'}{Open for reading exclusively without compression.}
     \lineii{'r:gz'}{Open for reading with gzip compression.}
     \lineii{'r:bz2'}{Open for reading with bzip2 compression.}
-    \lineii{'a' or 'a:'}{Open for appending with no compression.}
+    \lineii{'a' or 'a:'}{Open for appending with no compression. The file
+        is created if it does not exist.}
     \lineii{'w' or 'w:'}{Open for uncompressed writing.}
     \lineii{'w:gz'}{Open for gzip compressed writing.}
     \lineii{'w:bz2'}{Open for bzip2 compressed writing.}