explain PTAL
diff --git a/CodeReview.md b/CodeReview.md
index 7516e6b..6f63bba 100644
--- a/CodeReview.md
+++ b/CodeReview.md
@@ -6,6 +6,7 @@
* ` LGTM ` — looks good to me
* ` SGTM ` — sounds good to me
+ * ` PTAL ` — please take a look
* ` s/foo/bar/ ` — please replace ` foo ` with ` bar `; this is [sed syntax](http://en.wikipedia.org/wiki/Sed#Usage).
* ` s/foo/bar/g ` — please replace ` foo ` with ` bar ` throughout your entire change
* `R=foo` — these messages are directives for the [Go release dashboard](https://swtch.com/godash/).
