+
+### Compatibility Variables
+
+The following configurations variables used by the backup-pull(1) script in job
+definition files are automatically mapped to the new backup-script variables:
+
+* host -> system
+* source -> source_root
+* pre_exec -> job_pre_exec
+* post_exec -> job_post_exec
+
+
+## Exit codes
+
+- 1: Unspecific Error!
+- 2: Usage information has been shown.
+- 3: Can't read system definition
+- 4: PID-file exists!
+- 5: Pre-exec command failed!
+- 6: There have been systems with errors!
+- 9: Aborted (CTRL-C)!