README

README.md

@@ -41,9 +41,10 @@ Features
 * A completed job does not get submitted again (to PBS)
 * A job already in the queue does not get submitted again to PBS
 * A completed job in the PBS queue does not run again
-* A running job is locked
+* A running job is locked - with expiry
 * Guarantee independently executed jobs
 * Do not worry about submitting serial jobs multiple times
+* When an output file changes (or is removed) once-only runs again
 
 and coming
 
@@ -192,6 +193,10 @@ once-only --skip-exe --skip-glob 'out*' --skip-glob '*.ph' muscle -in aa.fa -out
 
 For a full range of glob patterns, see this [page](http://ruby.about.com/od/beginningruby/a/dir2.htm).
 
+Using the --skip/--out options also defines the output files that get
+tested on the next invocation of once-only. If an output file goes
+missing or changes, once-only will run again.
+
 Sometimes you want to include input files that are not on the command
 line for generating the hash. Maybe some default input file name is
 being picked up, or it is defined in a configuration file. In that