diff --git a/Environment-Variables.md b/Environment-Variables.md
index ca691e0..1c78f26 100644
--- a/Environment-Variables.md
+++ b/Environment-Variables.md
@@ -9,6 +9,9 @@ export VOLUMEPREALLOCATE=true # or export VOLUMEPREALLOCATE=
 weed master
 ```
 
+# Weed prefix
+For `v`, `logtostderr`, `stderrthreshold`, `vmoudle`, `options`, `logdir`, `alsologtostderr`, `log_backtrace_at` , and `config_dir` you have to use `WEED_` as prefix for environment variable like this `WEED_CONFIG_DIR=/tmp`
+
 # Docker
 This is useful for using docker and docker compose  
 You have to override entrypoint to `weed` because defautl [entrypoint](https://github.com/seaweedfs/seaweedfs/blob/master/docker/entrypoint.sh) use default values for `volumeSizeLimitMB`, `volumePreallocate`, `mdir`, `dir`, and `max` and setting environment variables won't change these values.