DIT structure rules can be specified with existing schema components and don't require additional code for implementation.

The following formal specification for attribute types is provided in RFC 4512, section

DITStructureRuleDescription = "(" wsp
ruleid                      ; object identifier
[ sp "NAME" sp qdescrs ]    ; short name descriptor
[ sp "DESC" sp qdstring ]   ; description
[ sp "OBSOLETE" ]           ; specifies if the rule is inactive
sp "FORM" sp oid            ; OID or name form with which the rule is associated
[ sp "SUP" ruleids ]        ; Superior rule IDs
extensions wsp ")"          ; extensions followed by a white space and ")"

The following extensions are specific to PingDirectory Server and are not defined in RFC 4512.

extensions = / 
"X-ORIGIN" /             ; Specifies where the rule is defined
"X-SCHEMA-FILE" /        ; Specifies which schema file contains the definition
"X-READ-ONLY"            ; True or False. Specifies if the file that contains 
                         ;   the schema element is marked as read-only in
                         ;   the server configuration.