diff --git a/README.md b/README.md
index 6e4ca21..438e163 100644
--- a/README.md
+++ b/README.md
@@ -45,7 +45,7 @@ Implementation
 
 ### ULID
 
-The ULID is a 128 bit long identifier. The first 48 bits represent the count of milliseconds since Unix Epoch, 1 January 1970. The remaining 60 bits are generated by a secure random number generator.
+The ULID is a 128 bit long identifier. The first 48 bits represent the count of milliseconds since Unix Epoch, 1970-01-01. The remaining 80 bits are generated by a secure random number generator.
 
 ```java
 // Generate a ULID
@@ -84,7 +84,7 @@ Sequence of ULIDs:
 
 ### Monotonic ULID
 
-The Monotonic ULID is a 128 bit long identifier. The first 48 bits represent the count of milliseconds since Unix Epoch, 1 January 1970. The remaining 60 bits are generated by a secure random number generator.
+The Monotonic ULID is a 128 bit long identifier. The first 48 bits represent the count of milliseconds since Unix Epoch, 1970-01-01. The remaining 80 bits are generated by a secure random number generator.
 
 The random component is incremented by 1 whenever the current millisecond is equal to the previous one. But when the current millisecond is different, the random component changes to another random value.
 
@@ -180,7 +180,7 @@ Get the random component of a ULID:
 byte[] random = ulid.getRandom(); // 10 bytes (80 bits)
 ```
 
-Use a `UlidFctory` instance with `java.util.Random` to generate ULIDs:
+Use a `UlidFactory` instance with `java.util.Random` to generate ULIDs:
 
 ```java
 Random random = new Random();
@@ -189,7 +189,7 @@ UlidFactory factory = UlidCreator.getDefaultFactory().withRandomGenerator(random
 Ulid ulid = facory.create();
 ```
 
-Use a `UlidFctory` instance with any random generator you like(*) to generate ULIDs:
+Use a `UlidFactory` instance with any random generator you like(*) to generate ULIDs:
 
 ```java
 import com.github.niceguy.random.AwesomeRandom; // a hypothetical RNG
diff --git a/pom.xml b/pom.xml
index aad277f..036a865 100644
--- a/pom.xml
+++ b/pom.xml
@@ -3,7 +3,7 @@
 
 	<groupId>com.github.f4b6a3</groupId>
 	<artifactId>ulid-creator</artifactId>
-	<version>3.0.1</version>
+	<version>3.0.2-SNAPSHOT</version>
 	<packaging>jar</packaging>
 
 	<name>ulid-creator</name>
@@ -44,7 +44,7 @@
 		<url>https://github.com/f4b6a3/ulid-creator</url>
 		<connection>scm:git:ssh://git@github.com/f4b6a3/ulid-creator.git</connection>
 		<developerConnection>scm:git:ssh://git@github.com/f4b6a3/ulid-creator.git</developerConnection>
-		<tag>ulid-creator-3.0.1</tag>
+		<tag>HEAD</tag>
 	</scm>
 
 	<distributionManagement>
diff --git a/src/main/java/com/github/f4b6a3/ulid/Ulid.java b/src/main/java/com/github/f4b6a3/ulid/Ulid.java
index b2cf1ce..8c0563a 100644
--- a/src/main/java/com/github/f4b6a3/ulid/Ulid.java
+++ b/src/main/java/com/github/f4b6a3/ulid/Ulid.java
@@ -616,6 +616,8 @@ public final class Ulid implements Serializable, Comparable<Ulid> {
 	 * A valid ULID string is a sequence of 26 characters from Crockford's base 32
 	 * alphabet.
 	 * 
+	 * The first character of the input string must be between 0 and 7.
+	 * 
 	 * @param chars a char array
 	 * @return boolean true if valid
 	 */