<WS>                ::= ( '#' (~'\n')* '\n' | ' ' | '\t' | '\r' '\n' | '\n' | '\r' )
<QUOTE>             ::= '\''
<DIGIT>             ::= '0' .. '9'
<DOLLAR>            ::= '$'
<OPEN_PAREN>        ::= '('
<CLOSE_PAREN>       ::= ')'
<OPEN_BRACKET>      ::= '{'
<CLOSE_BRACKET>     ::= '}'
<NUMERIC_STRING>    ::= ('0' .. '9')+
<NUMERICOID>        ::= <NUMERIC_STRING ( '.' NUMERIC_STRING )+
<IDENTIFIER>        ::= ( 'a' .. 'z') ( 'a' .. 'z' | '0' .. '9' | '-' | ';' )*
<DESC>              ::= "desc" <WS> <QUOTE> ( ~'\'' )+ <QUOTE>

<SYNTAX>            ::= "syntax" <WS> <NUMERICOID> ( <OPEN_BRACKET> ( <DIGIT> )+ <CLOSE_BRACKET> )?

<parseSchema>       ::= ( <attributeType> | <objectClass> )*

<objectClass>       ::=
    "objectclass"
    <OPEN_PAREN> <NUMERICOID>
    ( <objectClassNames> )?
    ( <objectClassDesc> )?
    ( "OBSOLETE" )?
    ( <objectClassSuperiors> )?
    ( "ABSTRACT" | "STRUCTURAL" | "AUXILIARY" )?
    ( <must> )?
    ( <may> )?
    <CLOSE_PAREN>

<may>                   ::= "MAY" <woidlist>

<must>                  ::= "MUST" <woidlist>

<objectClassSuperiors>  ::= "SUP" <woidlist>

<woid>                  ::= ( <NUMERICOID> | <IDENTIFIER> )

<woidlist>              ::= ( <woid> | ( <OPEN_PAREN> <woid> ( <DOLLAR> <woid> )* <CLOSE_PAREN> ) )

<objectClassDesc>       ::= <DESC>

<objectClassNames>      ::=
    ( "NAME" ( <QUOTE> <IDENTIFIER> <QUOTE> |
    ( <OPEN_PAREN> <QUOTE> <IDENTIFIER> <QUOTE> ( <QUOTE> <IDENTIFIER> <QUOTE> )* <CLOSE_PAREN> ) ) )

<attributeType>         ::=
    "attributetype" <OPEN_PAREN> <NUMERICOID>
    ( <names> )?
    ( <desc> )?
    ( "OBSOLETE" )?
    ( <superior> )?
    ( <equality> )?
    ( <ordering> )?
    ( <substr> )?
    ( <syntax> )?
    ( "SINGLE-VALUE" )?
    ( "COLLECTIVE" )?
    ( "NO-USER-MODIFICATION" )?
    ( <usage> )?
    <CLOSE_PAREN>

<desc>                  ::= <DESC>

<superior>              ::= "SUP" ( <NUMERICOID> | <IDENTIFIER> );

<equality>              ::= "EQUALITY" ( <NUMERICOID> | <IDENTIFIER> );

<substr>                ::= "SUBSTR" ( <NUMERICOID> | <IDENTIFIER> )

<ordering>              ::= "ORDERING" ( <NUMERICOID> | <IDENTIFIER> )

<names>                 ::= "NAME" ( <QUOTE> <IDENTIFIER> <QUOTE> | ( <OPEN_PAREN> ( <QUOTE> <IDENTIFIER> <QUOTE> )+ <CLOSE_PAREN> ) )

<syntax>                ::= <SYNTAX>

<usage>                 ::= "USAGE" ( "userApplications" | "directoryOperation" | "distributedOperation" | "dSAOperation" ) SyntaxDescription

SyntaxDescription = <LPAREN> <WSP>
    ::= <OPEN_PAREN>   <WS> <numericoid>
         ( <SP><WS> "DESC" <SP> <qdstring> )?
         <WSP> <RPAREN> <WS> <CLOSE_PAREN>