diff --git a/README.md b/README.md
index c679c3d..f397a75 100644
--- a/README.md
+++ b/README.md
@@ -2,3 +2,9 @@
 Repo for jtreg tests which belongs to jdk/tests, but they were in rush, or not eligible, and later forgotten.
 
 Some tests are fips-incomaptible, but the detection is now weak. you can pretend fips mode by setting OTOOL_cryptosetup=fips. This may (and should) change in future.
+
+Some of the tests are noot applicable to all systems/jdks. This is controled by standard, and extended @requires. The extended one is simple, environment varibales one:
+ * RH_JDK=true wills set var.rh.jdk to true, which **enables** aprox 6 more tests which are known to work only on Red Hat jdks
+ * MSYS2_ENABLED=true wills set var.msys2.enabled to trueand that will **disable** aprox 13 tests, which are known to fail on windows subsystem for linux
+
+Note, that thsoe is workaround, and on long run all such exceses hshould be removed