diff --git a/src/main/java/com/noorq/casser/mapping/annotation/Constraint.java b/src/main/java/com/noorq/casser/mapping/annotation/Constraint.java
new file mode 100644
index 0000000..9496f24
--- /dev/null
+++ b/src/main/java/com/noorq/casser/mapping/annotation/Constraint.java
@@ -0,0 +1,237 @@
+/*
+ *      Copyright (C) 2015 Noorq, Inc.
+ *
+ *   Licensed under the Apache License, Version 2.0 (the "License");
+ *   you may not use this file except in compliance with the License.
+ *   You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing, software
+ *   distributed under the License is distributed on an "AS IS" BASIS,
+ *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *   See the License for the specific language governing permissions and
+ *   limitations under the License.
+ */
+package com.noorq.casser.mapping.annotation;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Constraint annotations are using for data integrity mostly for @java.lang.String types.  
+ * The place of the annotation is the particular method in model interface.
+ * 
+ * All of them does not have effect on selects and data retrieval operations.
+ * 
+ * Support types: 
+ * - @NotNull supports any @java.lang.Object type
+ * - All annotations support @java.lang.String type
+ * 
+ * @author Albert Shift
+ *
+ */
+
+public final class Constraint {
+
+	private Constraint() {
+	}
+
+	/**
+	 *  NotNull annotation is using to check that value is not null before storing it 
+	 *  
+	 *  It does not check on selects and data retrieval operations
+     *
+	 */
+	
+	@Documented
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
+	public @interface NotNull {
+
+	}
+	
+	/**
+	 *  NotEmptyText annotation is using to check that value has text before storing it 
+	 *  
+	 *  It does not check on selects and data retrieval operations
+     *
+	 */
+	
+	@Documented
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
+	public @interface NotEmptyText {
+
+	}
+	
+	/**
+	 *  Email annotation is using to check that value has a valid email before storing it 
+	 *  
+	 *  It does not check on selects and data retrieval operations
+     *
+	 */
+	
+	@Documented
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
+	public @interface Email {
+
+	}
+	
+	/**
+	 *  Number annotation is using to check that all letters in value are digits before storing it 
+	 *  
+	 *  It does not check on selects and data retrieval operations
+     *
+	 */
+	
+	@Documented
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
+	public @interface Number {
+
+	}
+	
+	
+	/**
+	 *  Alphabet annotation is using to check that all letters in value are in specific alphabet before storing it 
+	 *  
+	 *  It does not check on selects and data retrieval operations
+     *
+	 */
+	
+	@Documented
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
+	public @interface Alphabet {
+
+		char[] value();
+		
+	}
+	
+	/**
+	 *  Length annotation is using to ensure that value has exact length before storing it
+	 *
+	 *  It does not have effect on selects and data retrieval operations
+	 *
+	 */
+	
+	@Documented
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
+	public @interface Length {
+
+		int value();
+		
+	}
+	
+	/**
+	 *  MaxLength annotation is using to ensure that value has length less or equal to some threshold before storing it
+	 *
+	 *  It does not have effect on selects and data retrieval operations
+	 *
+	 */
+	
+	@Documented
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
+	public @interface MaxLength {
+
+		int value();
+		
+	}
+	
+	/**
+	 *  MinLength annotation is using to ensure that value has length greater or equal to some threshold before storing it
+	 *
+	 *  It does not have effect on selects and data retrieval operations
+	 *
+	 */
+	
+	@Documented
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
+	public @interface MinLength {
+
+		int value();
+		
+	}
+	
+	/**
+	 *  LowerCase annotation is using to ensure that value is in lower case before storing it
+	 *
+	 *  It does not have effect on selects and data retrieval operations
+	 *
+	 */		
+	
+	@Documented
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
+	public @interface LowerCase {
+
+	}
+
+	/**
+	 *  UpperCase annotation is using to ensure that value is in upper case before storing it
+	 *
+	 *  It does not have effect on selects and data retrieval operations
+	 *
+	 */	
+	
+	@Documented
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
+	public @interface UpperCase {
+
+	}
+	
+	/**
+	 *  Pattern annotation is LowerCase annotation is using to ensure that value is upper case before storing it
+	 *
+	 *  It does not have effect on selects and data retrieval operations
+	 *
+	 */	
+	
+	@Documented
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
+	public @interface Pattern {
+
+		/**
+		 * User defined regex expression to check match of the value
+		 * 
+		 * @return Regex pattern
+		 */
+		
+		String value();
+		
+	}
+	
+	/**
+	 *  Custom annotation is using special implementation to check value before storing it
+	 *
+	 *  It does not have effect on selects and data retrieval operations
+	 *
+	 */	
+	
+	@Documented
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
+	public @interface Custom {
+
+		/**
+		 * Defines class name of the custom implementation of the checker.
+		 * Class must implement special interface for this and be thread-safe and do not relay that it will be a singleton.
+		 * 
+		 * @return className of the custom implementation
+		 */
+		
+		String value();
+		
+	}
+	
+}
diff --git a/src/main/java/com/noorq/casser/mapping/annotation/Data.java b/src/main/java/com/noorq/casser/mapping/annotation/Data.java
deleted file mode 100644
index 413dfa6..0000000
--- a/src/main/java/com/noorq/casser/mapping/annotation/Data.java
+++ /dev/null
@@ -1,136 +0,0 @@
-/*
- *      Copyright (C) 2015 Noorq, Inc.
- *
- *   Licensed under the Apache License, Version 2.0 (the "License");
- *   you may not use this file except in compliance with the License.
- *   You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *   Unless required by applicable law or agreed to in writing, software
- *   distributed under the License is distributed on an "AS IS" BASIS,
- *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *   See the License for the specific language governing permissions and
- *   limitations under the License.
- */
-package com.noorq.casser.mapping.annotation;
-
-import java.lang.annotation.Documented;
-import java.lang.annotation.ElementType;
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
-import java.lang.annotation.Target;
-
-/**
- * Data annotations are using for data integrity. Annotations helps to build simple data model without complex operations in repositories. 
- * All of them are placing for particular columns under the methods in model DSL.
- * 
- * Some of them are using for validation only, like @NotNull or @Length 
- * Some of them, like @LowerCase and @UpperCase are doing actual modifications under the data and working as preprocessors.
- * 
- * All of them does not have effect on selects and data retrieval operations.
- * 
- * Support types: 
- * - @NotNull supports any @Object type
- * - All annotations support @String type
- * 
- * @author Albert Shift
- *
- */
-
-public final class Data {
-
-	private Data() {
-	}
-
-	/**
-	 *  NotNull annotation is using to check that value is not null before storing it 
-	 *  
-	 *  It does not check on selects and data retrieval operations
-     *
-	 */
-	
-	@Documented
-	@Retention(RetentionPolicy.RUNTIME)
-	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
-	public @interface NotNull {
-
-	}
-	
-	/**
-	 *  Length annotation is using to ensure that value has exact length before storing it
-	 *
-	 *  It does not have effect on selects and data retrieval operations
-	 *
-	 */
-	
-	@Documented
-	@Retention(RetentionPolicy.RUNTIME)
-	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
-	public @interface Length {
-
-		int value();
-		
-	}
-	
-	/**
-	 *  MaxLength annotation is using to ensure that value has length less or equal to some threshold before storing it
-	 *
-	 *  It does not have effect on selects and data retrieval operations
-	 *
-	 */
-	
-	@Documented
-	@Retention(RetentionPolicy.RUNTIME)
-	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
-	public @interface MaxLength {
-
-		int value();
-		
-	}
-	
-	/**
-	 *  MinLength annotation is using to ensure that value has length greater or equal to some threshold before storing it
-	 *
-	 *  It does not have effect on selects and data retrieval operations
-	 *
-	 */
-	
-	@Documented
-	@Retention(RetentionPolicy.RUNTIME)
-	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
-	public @interface MinLength {
-
-		int value();
-		
-	}
-	
-	/**
-	 *  LowerCase annotation is the preprocessor annotation that converts String value to lower case if it is not null
-	 *
-	 *  It does not have effect on selects and data retrieval operations
-	 *
-	 */		
-	
-	@Documented
-	@Retention(RetentionPolicy.RUNTIME)
-	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
-	public @interface LowerCase {
-
-	}
-
-	/**
-	 *  UpperCase annotation is the preprocessor annotation that converts String value to upper case if it is not null
-	 *
-	 *  It does not have effect on selects and data retrieval operations
-	 *
-	 */	
-	
-	@Documented
-	@Retention(RetentionPolicy.RUNTIME)
-	@Target(value = { ElementType.METHOD, ElementType.ANNOTATION_TYPE })
-	public @interface UpperCase {
-
-	}
-	
-}