doc: document --backup-file in NEWS

diff --git a/NEWS b/NEWS
index 6905bd01fcfb5f169d1fc3b35a214ef2b3bdb416..345ee932cd41bfc8fcab00344eb470fd587ea92e 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,10 @@ flex NEWS
 
 ** scanner
 
+*** New option: --backup-file allows setting the name of the file
+    written containing backing up information. Useful if you need
+    backing up information multiple scanners in the same directory.
+
 *** flex emits correct line number directives when line numbers refer
     to the file containing the line number directives.