# HG changeset patch
# User Simon Sapin <simon.sapin@octobus.net>
# Date 1636134660 -3600
#      Fri Nov 05 18:51:00 2021 +0100
# Node ID ce0d4b8488c4326e861208d35c5e11ea100022cb
# Parent  5770844496bd3f6d87156802fabaef9f5bfe052e
Document cleanup

diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -8,4 +8,15 @@
 Usage
 -----
 
-See `./run --help`
+See `./run --help` and `./run <subcommand> --help`
+
+
+Cleanup
+-------
+
+`hg clean -i tmp` is safe to run any time Megafine is not running.
+It should usually do nothing, but might if a process was interrupted.
+
+`hg clean -i cache`  is safe to run any time Megafine is not running,
+at the cost of CPU time and/or network traffic
+to rebuild parts as they become needed again.