Reference
Every LDAP control, extended operation, attribute type, object class, syntax, and matching rule, indexed by its object identifier and cross-referenced to the RFC that defines it. Search by number or by name.
Controls change how a single LDAP operation behaves. A client attaches one to a request; a server advertises the ones it honors in the root DSE supportedControl attribute.
Extended operations add capabilities the core protocol never defined, from StartTLS to Password Modify. Servers list what they support in supportedExtension.
Features flag optional protocol behavior a server implements. They surface in the root DSE supportedFeatures attribute.
Messages a server sends without a matching client request, such as the Notice of Disconnection.
The fields an entry can hold: cn, mail, uidNumber, and several hundred more. Each has a syntax, matching rules, and an OID.
Object classes define which attributes an entry may and must carry, from top down to inetOrgPerson and posixAccount.
Syntaxes define how an attribute value is encoded and compared, from Directory String to Generalized Time.
Matching rules tell the server how to compare values for a syntax: equality, ordering, and substring.
Name forms specify which attributes an entry of a given structural object class may use in its RDN.
Administrative roles mark the subtrees where an administrative model (access control, collective attributes, subschema) applies, per RFC 3672.
2377 OIDs, sourced from the IANA LDAP Parameters registry. More categories and vendor schema (including Active Directory) are being added.