| Platform SDK: Active Directory, ADSI, and Directory Services |
Active Directory defines a set of attribute syntaxes for specifying the type of data contained by an attribute. The predefined syntaxes do not actually appear in the directory, and you cannot add new syntaxes. There are different ways to identify the syntax of an attribute class depending on what you want to do.
To determine the syntax of one of the predefined attribute classes, see the attribute's reference page in the Active Directory Schema Reference section of the Active Directory Reference.
The following tables describe the syntaxes supported by Active Directory and list the corresponding VARTYPE and ADSTYPE constants. There are tables for four syntax groups: simple data types, strings, time formats, and object references.
The following table shows the syntax for simple data types.
| Name | Description |
|---|---|
| Boolean | Boolean. For queries that include attributes of Boolean syntax in a filter, you must specify TRUE or FALSE (for example, myboolattr=TRUE).
attributeSyntax: 2.5.5.8 oMSyntax: 1 VARTYPE: VT_BOOL ADSTYPE: ADSTYPE_BOOLEAN |
| Enumeration | Defined by the ITU. Treated as an integer in Active Directory.
attributeSyntax: 2.5.5.9 oMSyntax: 10 VARTYPE: VT_I4 ADSTYPE: ADSTYPE_INTEGER |
| Integer | 32-bit integer.
attributeSyntax: 2.5.5.9 oMSyntax: 2 VARTYPE: VT_I4 ADSTYPE: ADSTYPE_INTEGER |
| INTEGER8 | Large integer. Use for 64-bit values.
attributeSyntax: 2.5.5.16 oMSyntax: 65 VARTYPE: VT_DISPATCH (QueryInterface for IADsLargeInteger) ADSTYPE: ADSTYPE_LARGE_INTEGER |
The following table shows the syntax for string data types.
| Name | Description |
|---|---|
| CaseExactString | A case-sensitive character string.
attributeSyntax: 2.5.5.3 oMSyntax: 27 VARTYPE: VT_BSTR ADSTYPE: ADSTYPE_CASE_EXACT_STRING |
| CaseIgnoreString | A case-insensitive string containing characters from the teletex character set.
attributeSyntax: 2.5.5.4 oMSyntax: 20 VARTYPE: VT_BSTR ADSTYPE: ADSTYPE_CASE_IGNORE_STRING |
| DirectoryString | A case-insensitive Unicode string.
attributeSyntax: 2.5.5.12 oMSyntax: 64 VARTYPE: VT_BSTR ADSTYPE: ADSTYPE_CASE_IGNORE_STRING |
| IA5String | A case-sensitive string containing characters from the IA5 character set.
attributeSyntax: 2.5.5.5 oMSyntax: 22 VARTYPE: VT_BSTR ADSTYPE: ADSTYPE_PRINTABLE_STRING |
| NTSecurityDescriptor | Octet string containing a Windows NT/Windows 2000 security descriptor.
attributeSyntax: 2.5.5.15 oMSyntax: 66 VARTYPE: VT_DISPATCH (QueryInterface for IADsSecurityDescriptor) ADSTYPE: ADSTYPE_NT_SECURITY_DESCRIPTOR |
| NumericString | String containing digits.
attributeSyntax: 2.5.5.6 oMSyntax: 18 VARTYPE: VT_BSTR ADSTYPE: ADSTYPE_NUMERIC_STRING |
| OctetString | Array of bytes. Use OctetString to store binary data.
attributeSyntax: 2.5.5.10 oMSyntax: 4 VARTYPE: VT_UI1 | VT_ARRAY ADSTYPE: ADSTYPE_OCTET_STRING |
| OID | An object identifier (OID) string, which is a string containing digits (0-9) and decimal points (.).
attributeSyntax: 2.5.5.2 oMSyntax: 6 VARTYPE: VT_BSTR ADSTYPE: ADSTYPE_CASE_IGNORE_STRING |
| PrintableString | A case-sensitive string containing characters from the printable character set.
attributeSyntax: 2.5.5.5 oMSyntax: 19 VARTYPE: VT_BSTR ADSTYPE: ADSTYPE_PRINTABLE_STRING |
| Sid | Octet string containing a security identifier (SID). Use this syntax to store SID values only.
attributeSyntax: 2.5.5.17 oMSyntax: 4 VARTYPE: VT_UI1 | VT_ARRAY ADSTYPE: ADSTYPE_OCTET_STRING |
The following table shows the syntax for the time data types. If you are defining a new attribute to store time values, use the GeneralizedTime syntax, which uses four characters to represent the year instead of only two. For descriptions of the GeneralizedTime and UTCTime formats, see How To Specify Comparison Values.
| Name | Description |
|---|---|
| GeneralizedTime | A time string format defined by ASN.1 standards. See ISO 8601 and X680. Use this syntax for storing time values in Generalized-Time format.
attributeSyntax: 2.5.5.11 oMSyntax: 24 VARTYPE: VT_DATE ADSTYPE: ADSTYPE_UTC_TIME |
| UTCTime | A time string format defined by ASN.1 standards. See ISO 8601 and X680. Use this syntax for storing time values in UTC-Time format.
attributeSyntax: 2.5.5.11 oMSyntax: 23 VARTYPE: VT_DATE ADSTYPE: ADSTYPE_UTC_TIME |
The following table shows the syntax for the object reference data types.
| Name | Description |
|---|---|
| AccessPointDN | From X400.
attributeSyntax: 2.5.5.14 oMSyntax: 127 oMObjectClass: 0x2B0C0287731C00853E |
| DN | String containing a distinguished name (DN). For attributes with this syntax, Active Directory treats attribute values as references to the object identified by the DN and automatically updates the value if the object is moved or renamed. For queries that include attributes of DN syntax in a filter, you must specify full distinguished names—wildcards (for example, cn=John*) are not supported.
attributeSyntax: 2.5.5.1 oMSyntax: 127 oMObjectClass: 0x2B0C0287731C00854A VARTYPE: VT_BSTR ADSTYPE: ADSTYPE_DN_STRING |
| DNWithBinary | An OctetString containing a binary value and a distinguished name (DN). A value with this syntax has the following format:
B:CharCount:binaryvalue:ObjectDN where binaryvalue is the hexidecimal representation of the binary value, CharCount is the number of hexadecimal digits in binaryvalue, and ObjectDN is a distinguished name. Active Directory automatically updates the DN if the object that it refers to is moved or renamed. For an example that uses this syntax, see Enabling Rename-safe Binding with the otherWellKnownObjects Property. attributeSyntax: 2.5.5.17 oMSyntax: 127 oMObjectClass: 0x2A864886F7140101010B VARTYPE: VT_DISPATCH (QueryInterface for IADsDNWithBinary) ADSTYPE: ADSTYPE_DN_WITH_BINARY |
| DNWithString | An OctetString containing a string value and a distinguished name (DN). A value with this syntax has the following format:
S:CharCount:stringvalue:ObjectDN where CharCount is the number of characters in the stringvalue string, and ObjectDN is a distinguished name of an object in Active Directory. Active Directory automatically updates the DN if the object that it refers to is moved or renamed. attributeSyntax: 2.5.5.14 oMSyntax: 127 oMObjectClass: 0x2A864886F7140101010C VARTYPE: VT_DISPATCH (QueryInterface for IADsDNWithString) ADSTYPE: ADSTYPE_DN_WITH_STRING |
| ORName | From X400.
attributeSyntax: 2.5.5.7 oMSyntax: 127 oMObjectClass: 0x56060102050B1D |
| PresentationAddress | A string for containing OSI presentation addresses.
attributeSyntax: 2.5.5.13 oMSyntax: 127 oMObjectClass: 0x2B0C0287731C00855C VARTYPE: VT_BSTR ADSTYPE: ADSTYPE_CASE_IGNORE_STRING |
| ReplicaLink | System only. Used by Active Directory.
attributeSyntax: 2.5.5.10 oMSyntax: 127 oMObjectClass: 0x2A864886F71401010106 VARTYPE: VT_VARIANT ADSTYPE: ADSTYPE_OCTET_STRING |