diff --git a/extension-fields.yml b/extension-fields.yml
new file mode 100644
index 0000000..65d93a6
--- /dev/null
+++ b/extension-fields.yml
@@ -0,0 +1,13 @@
+# Extension fields for avoid repetitions inside compose files.
+x-logging:
+  &default-logging
+  driver: local
+  options:
+    max-size: "1m"
+    max-file: "50"
+
+x-opt-values:
+  &volume-opt
+  driver_opts: &options
+    type: "nfs"
+    o: "addr=${IP},rw"