請問這是什麼意思？

bluefish

/schema/core.schema: line 31: attribute type "2.5.18.1" is operational

core.schema內容：

attributetype ( 2.5.18.1 NAME 'createTimestamp'
        EQUALITY generalizedTimeMatch
        ORDERING generalizedTimeOrderingMatch
        SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
        SINGLE-VALUE NO-USER-MODIFICATION USAGE directoryOperation )

attributetype ( 2.5.18.2 NAME 'modifyTimestamp'
        EQUALITY generalizedTimeMatch
        ORDERING generalizedTimeOrderingMatch
        SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
        SINGLE-VALUE NO-USER-MODIFICATION USAGE directoryOperation )

attributetype ( 2.5.18.3 NAME 'creatorsName'
        EQUALITY distinguishedNameMatch
        SYNTAX 1.3.6.1.4.1.1466.115.121.1.12
        SINGLE-VALUE NO-USER-MODIFICATION USAGE directoryOperation )

attributetype ( 2.5.18.4 NAME 'modifiersName'
        EQUALITY distinguishedNameMatch
        SYNTAX 1.3.6.1.4.1.1466.115.121.1.12
        SINGLE-VALUE NO-USER-MODIFICATION USAGE directoryOperation )

attributetype ( 2.5.18.10 NAME 'subschemaSubentry'
        EQUALITY distinguishedNameMatch
        SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 NO-USER-MODIFICATION
        SINGLE-VALUE USAGE directoryOperation )