Abstract

NEPOMUK Message Ontology extends the NEPOMUK Information Element framework into the domain of messages. Kinds of messages covered by NMO include Emails and instant messages. This document gives an overview of NMO and describes its classes and properties.

Status of this document

This document arose from the work of the Task-Force ontologies within the NEPOMUK project. This document is a DRAFT made available by the Nepomuk Consortium for discussion only. This document is a work in progress and may be updated, replaced, or rendered obsolete by other documents at any time.

This document is a part in a set of seven documents, which together comprise the complete specification of the Nepomuk Information Element Ontology Framework. These are: NIE, NFO, NCO, NMO, NCAL, NEXIF, NID3.

Ontology Visualisation

Change Log

  • Added
  • Modified
  • Deprecated
  • Introduction

    Messages - the domain of the Nepomuk Message Ontology (NMO) form a large part of the body of data available on a desktop. The user sends them, receives them, forwards them to other users, stores them and recalls them when they are needed. They are almost never self contained, always refering to something - to events, people, organizations, projects, activities, anything the user might be interested in. The purpose of NMO is to bring messages to the world of ontologies so that these links can be made explicit.

    The Concept of a Message

    The concept of a message in everyday english is broad. The Thesaurus.com website lists 'message' under 36 different meanings. NMO had to limit itself to a familiar domain of electronic communication. In NMO a message is a finite sequence of bytes containing arbitrary information exchanged between a sender and at least one receiver. Notice the difference between definitions of a Message and a File - the presence of at least one sender and receiver, and the absence of the requirement about durability. Of course it doesn't exclude the possibility of a file interpreted as a message (e.g. a .eml file).

    Even with these limitations, a taxonomy of messages can be defined. Subconcepts may include an Email, a message sent with an instant messaging application, an SMS, a voice message, a forum private message etc.

    A message can have multiple receivers. It can be sent to multiple Contacts. A mailing list is treated as one contact, since the message itself is sent to one email address. The fact that it is forwarded to other people is not expressed in the byte sequence that comprises the message and therefore falls beyond the scope of NIE. Blog posts and forum posts are not considered Messages in the NMO sense. This statement may seem arbitrary at first. In the case of a forum post, the actual Message according to the NMO definition (and the overall notion of nie:DataObject) is the HTTP packet generated by the browser and received by the Web Server. It is usually hardly relevant for a typical user. There are other ontologies, better suited towards description of blogs and forums, most notably SIOC.

    Description of a Message

    The most important information about each Message is the sender, receiver and the dates. NMO provides properties to express this information. The choice of those properties has been inspired by header fields found in emails, but they are definitely applicable to other kinds of messages too. The nmo:references property (\ref{nmo:references}) can be used to express relations in dialogues. It would link an answer with the message it refers to.

    Examples

    Example files that show how to use the expressive power of the ontology will be published here in near future.

    Ontology Classes Description

    Email

    Superclasses nie:InformationElement, nmo:Message, rdfs:Resource
    Subclasses --
    In domain of: nmo:bcc, nmo:cc, nmo:contentMimeType, nmo:emailBcc, nmo:emailCc, nmo:emailTo, nmo:to
    In range of: --
    Description An email.

    IMMessage

    Superclasses nie:InformationElement, nmo:Message, rdfs:Resource
    Subclasses --
    In domain of: --
    In range of: --
    Description A message sent with Instant Messaging software.

    Mailbox

    Superclasses nie:InformationElement, rdfs:Resource
    Subclasses --
    In domain of: --
    In range of: --
    Description A mailbox - container for MailboxDataObjects.

    MailboxDataObject

    Superclasses nie:DataObject, rdfs:Resource
    Subclasses --
    In domain of: --
    In range of: --
    Description An entity encountered in a mailbox. Most common interpretations for such an entity include Message or Folder

    Message

    Superclasses nie:InformationElement, rdfs:Resource
    Subclasses nmo:Email, nmo:IMMessage
    In domain of: nmo:from, nmo:hasAttachment, nmo:htmlMessageContent, nmo:inReplyTo, nmo:isRead, nmo:messageFrom, nmo:messageHeader, nmo:messageId, nmo:messageRecipient, nmo:messageReplyTo, nmo:messageSender, nmo:messageSubject, nmo:plainTextMessageContent, nmo:primaryMessageRecipient, nmo:primaryRecipient, nmo:receivedDate, nmo:recipient, nmo:references, nmo:replyTo, nmo:secondaryMessageRecipient, nmo:secondaryRecipient, nmo:sender, nmo:sentDate
    In range of: nmo:inReplyTo, nmo:references
    Description A message. Could be an email, instant messanging message, SMS message etc.

    MessageHeader

    Superclasses rdfs:Resource
    Subclasses --
    In domain of: nmo:headerName, nmo:headerValue
    In range of: nmo:messageHeader
    Description An arbitrary message header.

    MimeEntity

    Superclasses nie:InformationElement, rdfs:Resource
    Subclasses --
    In domain of: --
    In range of: --
    Description A MIME entity, as defined in RFC2045, Section 2.4.

    Ontology Properties Description

    bcc

    Type rdf:Property, rdfs:Resource
    Domain nmo:Email
    Range nco:Contact
    Superproperties nmo:recipient, nmo:secondaryRecipient
    Subproperties --
    Description deprecated in favor of nmo:emailBcc

    cc

    Type rdf:Property, rdfs:Resource
    Domain nmo:Email
    Range nco:Contact
    Superproperties nmo:recipient, nmo:secondaryRecipient
    Subproperties --
    Description deprecated in favor of nmo:emailCc

    contentMimeType

    Type rdf:Property, rdfs:Resource
    Domain nmo:Email
    Range xsd:string
    Maximal cardinality 1
    Superproperties nie:mimeType
    Subproperties --
    Description Key used to store the MIME type of the content of an object when it is different from the object's main MIME type. This value can be used, for example, to model an e-mail message whose mime type is"message/rfc822", but whose content has type "text/html". If not specified, the MIME type of the content defaults to the value specified by the 'mimeType' property.

    emailBcc

    Type rdf:Property, rdfs:Resource
    Domain nmo:Email
    Range nco:ContactMedium
    Superproperties nmo:messageRecipient, nmo:secondaryMessageRecipient
    Subproperties --
    Description A Contact that is to receive a bcc of the email. A Bcc (blind carbon copy) is a copy of an email message sent to a recipient whose email address does not appear in the message.

    emailCc

    Type rdf:Property, rdfs:Resource
    Domain nmo:Email
    Range nco:ContactMedium
    Superproperties nmo:messageRecipient, nmo:secondaryMessageRecipient
    Subproperties --
    Description A Contact that is to receive a cc of the email. A cc (carbon copy) is a copy of an email message whose recipient appears on the recipient list, so that all other recipients are aware of it.

    emailTo

    Type rdf:Property, rdfs:Resource
    Domain nmo:Email
    Range nco:ContactMedium
    Superproperties nmo:messageRecipient, nmo:primaryMessageRecipient
    Subproperties --
    Description The primary intended recipient of an email.

    from

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nco:Contact
    Superproperties --
    Subproperties --
    Description deprecated in favor of nmo:messageFrom

    hasAttachment

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nfo:Attachment
    Superproperties dcterms:hasPart, nie:hasPart, nie:relatedTo, dc:relation
    Subproperties --
    Description Links a message with files that were sent as attachments.

    headerName

    Type rdf:Property, rdfs:Resource
    Domain nmo:MessageHeader
    Range xsd:string
    Maximal cardinality 1
    Superproperties --
    Subproperties --
    Description Name of the message header.

    headerValue

    Type rdf:Property, rdfs:Resource
    Domain nmo:MessageHeader
    Range xsd:string
    Maximal cardinality 1
    Superproperties --
    Subproperties --
    Description Value of the message header.

    htmlMessageContent

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range xsd:string
    Superproperties nie:htmlContent
    Subproperties --
    Description HTML representation of the body of the message. For multipart messages, all parts are concatenated into the value of this property. Attachments, whose mimeTypes are different from text/plain or message/rfc822 are considered separate DataObjects and are therefore not included in the value of this property.

    inReplyTo

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nmo:Message
    Maximal cardinality 1
    Superproperties nmo:references
    Subproperties --
    Description Signifies that a message is a reply to another message. This feature is commonly used to link messages into conversations. Note that it is more specific than nmo:references. See RFC 2822 sec. 3.6.4

    isRead

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range xsd:boolean
    Maximal cardinality 1
    Superproperties --
    Subproperties --
    Description A flag that states the fact that a MailboxDataObject has been read.

    messageFrom

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nco:ContactMedium
    Maximal cardinality 1
    Superproperties --
    Subproperties --
    Description The sender of the message

    messageHeader

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nmo:MessageHeader
    Superproperties --
    Subproperties --
    Description Links the message with an arbitrary message header.

    messageId

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range xsd:string
    Superproperties nie:identifier, dc:identifier, nao:identifier
    Subproperties --
    Description An identifier of a message. This property has been inspired by the message-id property defined in RFC 2822, Sec. 3.6.4. It should be used for all kinds of identifiers used by various messaging applications to connect multiple messages into conversations. For email messageids, values are according to RFC2822/sec 3.6.4 and the literal value in RDF must include the brackets.

    messageRecipient

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nco:ContactMedium
    Superproperties --
    Subproperties nmo:emailBcc, nmo:emailCc, nmo:emailTo, nmo:messageSender, nmo:primaryMessageRecipient, nmo:secondaryMessageRecipient
    Description A common superproperty for all properties that link a message with its recipients. Please don't use this property directly.

    messageReplyTo

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nco:ContactMedium
    Maximal cardinality 1
    Superproperties --
    Subproperties --
    Description An address where the reply should be sent.

    messageSender

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nco:ContactMedium
    Maximal cardinality 1
    Superproperties nmo:messageRecipient
    Subproperties --
    Description The person or agent submitting the message to the network, if other from the one given with the nmo:from property. Defined in RFC 822 sec. 4.4.2

    messageSubject

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range xsd:string
    Maximal cardinality 1
    Superproperties dc:subject, nie:subject
    Subproperties --
    Description The subject of a message

    plainTextMessageContent

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range xsd:string
    Superproperties nie:plainTextContent
    Subproperties --
    Description Plain text representation of the body of the message. For multipart messages, all parts are concatenated into the value of this property. Attachments, whose mimeTypes are different from text/plain or message/rfc822 are considered separate DataObjects and are therefore not included in the value of this property.

    primaryMessageRecipient

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nco:ContactMedium
    Superproperties nmo:messageRecipient
    Subproperties nmo:emailTo
    Description The primary intended recipient of a message.

    primaryRecipient

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nco:Contact
    Superproperties nmo:recipient
    Subproperties nmo:to
    Description deprecated in favor of primaryMessageRecipient

    receivedDate

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range xsd:dateTime
    Maximal cardinality 1
    Superproperties dc:date
    Subproperties --
    Description Date when this message was received.

    recipient

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nco:Contact
    Superproperties --
    Subproperties nmo:bcc, nmo:cc, nmo:primaryRecipient, nmo:secondaryRecipient, nmo:sender, nmo:to
    Description deprecated in favor of nmo:messageRecipient

    references

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nmo:Message
    Superproperties --
    Subproperties nmo:inReplyTo
    Description Signifies that a message references another message. This property is a generic one. See RFC 2822 Sec. 3.6.4

    replyTo

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nco:Contact
    Superproperties --
    Subproperties --
    Description deprecated in favor of nmo:messageReplyTo

    secondaryMessageRecipient

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nco:ContactMedium
    Superproperties nmo:messageRecipient
    Subproperties nmo:emailBcc, nmo:emailCc
    Description A superproperty for all "additional" recipients of a message.

    secondaryRecipient

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nco:Contact
    Superproperties nmo:recipient
    Subproperties nmo:bcc, nmo:cc
    Description deprecated in favor of nmo:secondaryMessageRecipient

    sender

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range nco:Contact
    Superproperties nmo:recipient
    Subproperties --
    Description deprecated in favor of nmo:messageSender

    sentDate

    Type rdf:Property, rdfs:Resource
    Domain nmo:Message
    Range xsd:dateTime
    Maximal cardinality 1
    Superproperties nao:annotation, nie:contentCreated, nie:contentModified, nao:created, dc:date, nie:informationElementDate, nao:modified, dcterms:modified
    Subproperties --
    Description Date when this message was sent.

    to

    Type rdf:Property, rdfs:Resource
    Domain nmo:Email
    Range nco:Contact
    Superproperties nmo:primaryRecipient, nmo:recipient
    Subproperties --
    Description deprecated in favor of nmo:emailTo