The LDAP-specific encoding of a value of this syntax is the unconverted string of characters, which conforms to the <IA5String> rule in Section 3.2 of RFC 4517.
IA5String syntax corresponds to the X.500 ASN.1 Data type
The LDAP-specific encoding of a value of this syntax is defined by the IA5String rule in RFC 4512.
The OID for IA5String is 1.3.6.1.4.1.1466.115.121.1.26
Microsoft Active Directory uses OID 2.5.5.5 (ADSTYPE_CASE_IGNORE_STRING)
IA5String has an OMSyntax of 22