diff --git a/README.md b/README.md
index 025bcdc..f5a2a97 100755
--- a/README.md
+++ b/README.md
@@ -69,7 +69,7 @@ $ gdp publish
 
 ### Supported tag's format
 - [semantic version](https://semver.org/): e.g. v1.2.3 or 1.2.3
-- date version: e.g. 20180525.1
+- date version: e.g. 20180525.1 or release_20180525
 
 ### How to create generate note
 Release note content is generated based on merge commit messages.
diff --git a/format.go b/format.go
index d56b856..a8eccd3 100644
--- a/format.go
+++ b/format.go
@@ -27,7 +27,7 @@ func GetNextVersion(tag string) (string, error) {
 		return strings.Join(tags, "."), nil
 	}
 
-	// date version(e.g. 20180525.1)
+	// date version(e.g. 20180525.1 or release_20180525.1)
 	const layout = "20060102"
 	today := time.Now().Format(layout)