diff --git a/SQL Server 2012.md b/SQL Server 2012.md
index 11f04b1..32eb955 100644
--- a/SQL Server 2012.md	
+++ b/SQL Server 2012.md	
@@ -2,34 +2,43 @@
 
 
 ## SQL Server Object Name
-| Object                    | Notation   | Length | Plural | Prefix | Suffix | Abbreviation | Char Mask  | Example                          |
-| ------------------------- | ---------- | ------ | ------ | ------ | ------ | ------------ | ---------- | -------------------------------- |
-| Database                  | UPPERCASE  |     30 | No     | No     | No     | Yes          | [A-z]      | MYDATABASE                       |
-| Database Trigger          | PascalCase |    128 | No     | DTR_   | No     | Yes          | [A-z]      | DTR_CheckLogin                   |
-| Schema                    | lowercase  |     30 | No     | No     | No     | Yes          | [A-z][0-9] | myschema                         |
-| File Table                | PascalCase |    128 | No     | FT_    | No     | Yes          | [A-z][0-9] | FT_MyTable                       |
-| Temporary Table           | PascalCase |    118 | No     | No     | No     | Yes          | [A-z][0-9] | #MyTable                         |
-| Table                     | PascalCase |     30 | No     | No     | No     | Yes          | [A-z][0-9] | MyTable                          |
-| Table Default Values      | PascalCase |    128 | No     | DF_    | No     | Yes          | [A-z][0-9] | DF_MyTable_MyField               |
-| Table Primary Key         | PascalCase |    128 | No     | PK_    | No     | Yes          | [A-z][0-9] | PK_MyTableID                     |
-| Table Alternative Key     | PascalCase |    128 | No     | AK_    | No     | Yes          | [A-z][0-9] | AK_MyTable_MyField_AnotherFeild  |
-| Table Foreign Key         | PascalCase |    128 | No     | FK_    | No     | Yes          | [A-z][0-9] | FK_MyTable_ForeignTableID        |
-| Table Clustered Index     | PascalCase |    128 | No     | IXC_   | No     | Yes          | [A-z][0-9] | IXC_MyTable_MyField_AnotherFeild |
-| Table Non Clustered Index | PascalCase |    128 | No     | IX_    | No     | Yes          | [A-z][0-9] | IX_MyTable_MyField_AnotherFeild  |
-| Table Trigger             | PascalCase |    128 | No     | TR_    | No     | Yes          | [A-z][0-9] | TR_MyTable_LogicalName           |
-| View                      | PascalCase |    128 | No     | VI_    | No     | No           | [A-z][0-9] | VI_LogicalName                   |
-| Stored Procedure          | PascalCase |    128 | No     | usp_   | No     | No           | [A-z][0-9] | usp_LogicalName                  |
-| User-Defined Functions    | PascalCase |    128 | No     | udf_   | No     | No           | [A-z][0-9] | udf_LogicalName                  |
-| Synonim                   | CamelCase  |    128 | No     | sy_    | No     | No           | [A-z][0-9] | sy_logicalName                   |
-
+| Object                        | Code | Notation   | Length | Plural | Prefix | Suffix | Abbreviation | Char Mask  | Example                          |
+| ----------------------------- | ---- | ---------- | ------ | ------ | ------ | ------ | ------------ | ---------- | -------------------------------- |
+| Database                      |      | UPPERCASE  |     30 | No     | No     | No     | Yes          | [A-z]      | MYDATABASE                       |
+| Database Trigger              |      | PascalCase |    128 | No     | DTR_   | No     | Yes          | [A-z]      | DTR_CheckLogin                   |
+| Schema                        |      | lowercase  |     30 | No     | No     | No     | Yes          | [A-z][0-9] | myschema                         |
+| File Table                    |      | PascalCase |    128 | No     | FT_    | No     | Yes          | [A-z][0-9] | FT_MyTable                       |
+| Temporary Table               |      | PascalCase |    118 | No     | No     | No     | Yes          | [A-z][0-9] | #MyTable                         |
+| Table                         | U    | PascalCase |     30 | No     | No     | No     | Yes          | [A-z][0-9] | MyTable                          |
+| Table Default Values          | D    | PascalCase |    128 | No     | DF_    | No     | Yes          | [A-z][0-9] | DF_MyTable_MyField               |
+| Table Check Column Constraint | C    | PascalCase |    128 | No     | CK_    | No     | Yes          | [A-z][0-9] | CK_MyTable_MyField               |
+| Table Check Table Constraint  | C    | PascalCase |    128 | No     | CTK_   | No     | Yes          | [A-z][0-9] | CTK_MyTable_MyField_AnotherFeild |
+| Table Primary Key             | PK   | PascalCase |    128 | No     | PK_    | No     | Yes          | [A-z][0-9] | PK_MyTableID                     |
+| Table Alternative Key         | UQ   | PascalCase |    128 | No     | AK_    | No     | Yes          | [A-z][0-9] | AK_MyTable_MyField_AnotherFeild  |
+| Table Foreign Key             | F    | PascalCase |    128 | No     | FK_    | No     | Yes          | [A-z][0-9] | FK_MyTable_ForeignTableID        |
+| Table Clustered Index         |      | PascalCase |    128 | No     | IXC_   | No     | Yes          | [A-z][0-9] | IXC_MyTable_MyField_AnotherFeild |
+| Table Non Clustered Index     |      | PascalCase |    128 | No     | IX_    | No     | Yes          | [A-z][0-9] | IX_MyTable_MyField_AnotherFeild  |
+| Table Trigger                 | TR   | PascalCase |    128 | No     | TR_    | No     | Yes          | [A-z][0-9] | TR_MyTable_LogicalName           |
+| View                          | V    | PascalCase |    128 | No     | VI_    | No     | No           | [A-z][0-9] | VI_LogicalName                   |
+| Stored Procedure              | P    | PascalCase |    128 | No     | usp_   | No     | No           | [A-z][0-9] | usp_LogicalName                  |
+| User-Defined Functions        | FN   | PascalCase |    128 | No     | udf_   | No     | No           | [A-z][0-9] | udf_LogicalName                  |
+| Synonim                       | SN   | camelCase  |    128 | No     | sy_    | No     | No           | [A-z][0-9] | sy_logicalName                   |
+| Sequence                      | SO   | PascalCase |    128 | No     | sq_    | No     | No           | [A-z][0-9] | sq_TableName                     |
                                                                            
 ## Offical Reference
  - [Database object TECHNET] (Limitations)
  - [User-Defined Functions MSDN]
  - [Synonim TECHNET]
- - [Primary and Foreign Key Constraints]
+ - [Primary and Foreign Key Constraints MSDN]
+ - [sys.objects MSDN]
+ - [Constraints TECHNET]
+ - [CHECK Constraint TECHNET]
+ 
  
 [Database object TECHNET]:http://technet.microsoft.com/en-us/library/ms172451%28v=sql.110%29.aspx
 [User-Defined Functions MSDN]:http://msdn.microsoft.com/en-us/library/ms191007.aspx
 [Synonim TECHNET]:http://technet.microsoft.com/en-us/library/ms187552(v=sql.110).aspx
-[Primary and Foreign Key Constraints]:http://msdn.microsoft.com/en-us/library/ms179610.aspx
+[Primary and Foreign Key Constraints MSDN]:http://msdn.microsoft.com/en-us/library/ms179610.aspx
+[sys.objects MSDN]:http://msdn.microsoft.com/en-us/library/ms190324.aspx
+[Constraints TECHNET]:http://technet.microsoft.com/en-us/library/ms189862%28v=sql.105%29.aspx
+[CHECK Constraint TECHNET]:http://technet.microsoft.com/en-us/library/ms188258%28v=sql.105%29.aspx
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