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+++ b/README.md
@@ -1,5 +1,9 @@
 # backup.sh
 
+Create incrimental backups using rsync and filesystem hardlinking.
+
+requires: rsync, cron and a filesystem that is capable of hardlinking.
+
 ### Usage
 ```bash
 ./backup.sh <source dir> <destination dir>/<frequency> <number of backups to keep>