The PingDirectory Server stores its schema as a set of LDIF files for a Directory Server instance in the <server-root>/config/schema directory. The Directory Server reads the schema files in alphanumeric order at startup, so that the 00-core.ldif file is read first, then 01-pwpolicy.ldif, and then the rest of the files. Custom schema files should be named so that they are loaded in last. For example, custom schema elements could be saved in a file labelled 99-user.ldif, which loads after the default schema files are read at startup.

The Directory Server then uses the schema definitions to determine any violations that may occur during add, modify, or import requests. Clients applications check the schema (i.e., matching rule definitions) to determine the assertion value algorithm used in comparison or search operations.

The default set of schema files are present at installation and should not be modified. Modifying the default schema files could result in an inoperable server.

The schema files have the following descriptions:
Schema Files Description
00-core.ldif Governs the Directory Server's core functions.
01-pwpolicy.ldif Governs password policies.
02-config.ldif Governs the Directory Server's configuration.
03-changelog.ldif Governs the Directory Server's change log.
03-rfc2713.ldif Governs Java objects.
03-rfc2714.ldif Governs Common Object Request Broker Architecture (CORBA) object references.
03-rfc2739.ldif Governs calendar attributes for vCard.
03-rfc2926.ldif Governs Server Location Protocol (SLP) mappings to and from LDAP schemas.
03-rfc2985.ldif Governs PKCS #9 public-key cryptography.
03-rfc3112.ldif Governs LDAP authentication passwords.
03-rfc3712.ldif Governs printer services.
03-uddiv3.ldif Governs web services registries of SOA components.
04-rfc2307bis.ldif Governs mapping entities from TCP/IP and UNIX into X.500 entries.