X-Git-Url: http://nitlanguage.org

diff --git a/tests/README.md b/tests/README.md
index 5a6f51c..8941587 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -17,6 +17,8 @@ This directory contains small Nit programs and useful scripts to test the non re
   Useful before committing something.
 * `listfull.sh` lists tests that are run by `testfull.sh`.
   It is used by other scripts but can be used by human to see what is tested.
+  Each path is quoted using apostrophes, with `'\''` escaping an apostrophe.
+  This syntax is compatible with `xargs` and the POSIX shell.
 
   Currently, all files in `tests/`, `lib/` and `examples/` are executed, some of `contrib/` and the main programs of `src/`.
   To update the list of tested files, just edit this script.
@@ -154,11 +156,14 @@ It is a failure, and analogous to the standard `fail`.
 
 `[todo] out/zzz_test_todo.res -> not yet implemented`
 
-The produced result file contains the magic string "NOT YET IMPLEMENTED".
+The produced result file contains a magic string, like `NOT YET IMPLEMENTED`.
 Those are considered the same as expected errors (like a fixme)
 It is a success.
 
-Some engines, libraries or program just print this to simplify the management of tests.
+The magic strings are listed in `todo` files in the root and `sav` directories.
+They are used by engines, libraries or program just print this to simplify the management of tests.
+
+Magic strings are used with `grep -f`, so each line is a pattern that is searched within the res files.
 
 ### Skipped
 
@@ -319,6 +324,11 @@ $ cat out/zzz_test_post_proc.res
 The environment variable `NIT_TESTING` is set to `true` during the execution of program tests.
 Some libraries of programs can use it to produce specific reproducible results ; or just to exit their executions.
 
+`NIT_TESTING_TESTS_SH` is set to `true` for tests ran by `tests.sh` only, not by nitunit.
+
+`NIT_TESTING_ID` is set to an integer value unique between concurrent executions of `tests.sh`.
+Use it to name files, database entries, open sockets in order to avoid race conditions.
+
 ~~~
 $ cat zzz_tests/zzz_test_envvar.nit
 $ ./tests.sh zzz_tests/zzz_test_envvar.nit