rfc767.txt

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       some users in the groups and some not.

    

2.2.  Message Objects

  In the documents of messages, we use a set of objects such as mailbox
  or date.  These objects are encoded in basic data elements.  Some
  objects are simple things like integers or character strings, other
  objects are more complex things like lists or property lists.  The
  following is a list of the objects used in messages.  The object
  descriptions are in alphabetical order.

  Account

    The account information.  Represented by a name element.

  Address

    Address is intended to contain the minimum information necessary to
    identify a user, and no more (compare with mailbox).

    An address is a property list which contains the following
    <name,value> pairs:

      name    description
      ----    -----------
      NET     network name
      HOST    host name
      USER    user name

    or:

      name    description
      ----    -----------
      MPM     mpm-identifier
      USER    user name

  Answer

    A yes (true) or no (false) answer to a question.  Represented by a
    boolean element.



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  BCC

    A list of mailboxes.  The addresses of those who receive "blind
    carbon copies" of the message.

  Body

    A data structure.  This may be as simple as a character string
    (represented by a name or text element), or complex structure of
    lists.  It may be encrypted in part or in whole.  Section 3.3
    describes some possible structured bodies.

  C

    A character.  Represented by a name element.

  CC

    A list of mailboxes.  When copies of a message are sent to others in
    addition to the addresses in the To object, those to whom the copies
    are sent will have their addresses recorded here.

  City

    A city.  Represented by a name element.

  Comments

    A comment string.  Represented by a text element.

  Count

    A count of items of some sort.  Represented by a integer element.

  Country

    A country.  Represented by a name element.













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  Date

    The date and time are represented according to the International
    Standards Organization (ISO) recommendations [19,20,21].  Taken
    together the ISO recommendations 2014, 3307, and 4031 result in the
    following representation of the date and time:

      yyyy-mm-dd-hh:mm:ss,fff+hh:mm

    Where yyyy is the four-digit year, mm is the two-digit month, dd is
    the two-digit day, hh is the two-digit hour in 24 hour time, mm is
    the two-digit minute, ss is the two-digit second, and fff is the
    decimal fraction of the second.  To this basic date and time is
    appended the offset from Greenwich as plus or minus hh hours and mm
    minutes.

    The time is local time and the offset is the difference between
    local time and Coordinated Universal Time (UTC).  To convert from
    local time to UTC algebraically subtract the offset from the local
    time.

    For example, when the time in
              Los Angeles is  14:25:00-08:00
              the UTC is      22:25:00

    or when the time in
              Paris is        11:43:00+01:00
              the UTC is      10:43:00

  Device

    A device name.  Represented by a name element.

  Document

    A property list of fields.

  Distribution Group

    An distribution group is a property list which contains the
    following <name,value> pair:

      name    description
      ----    -----------
      GROUP   document distribution group name

    This construct is used so that a distribution group will be a
    special case of a mailbox.


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  Facsimile Structure

    A facsimile data structure.  Represented by a property list.

  File

    A file name.  Represented by a name element.

  Format

    A format indicator.  Represented by a name element.

  From

    A list of mailboxes.  The From is the name of the author of a
    document.

  Graphics Structure

    A graphics data structure.  Represented by a property list.

  Group

    A document distribution group name.  Represented by a name element.

  Host

    A host name.  Represented by a name element.

  Ident

    The identifier of a person, usually their initials.  Represented by
    a name element.

  In-Reply-To

    The message identifier of previous message.  Represented by a text
    element.

  Internet Address

    This identifies a host in the ARPA internetwork environment.  The
    internet address is a 32 bit number, the higher order 8 bits
    identify the network, and the lower order 24 bits identify the host
    on that network [22].  For use in this format the internet address
    is divided into eight bit fields and the value of each field is
    represented in decimal digits.  For example, the ARPANET address of
    ISIE is 167837748 and is represented as 10,1,0,52.  Further, this


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    representation may be extended to include an address within a host,
    such as the TCP port of an MPM, for example, 10,1,0,52,0,45.

  Keywords

    The key terms used in this message.  Represented by a text element.

  Mailbox

    This is the destination address of a user of the internetwork mail
    system.  Mailbox contains information such as network, host,
    location, and local user identifier of the recipient of the message.
    The mailbox may contain information in addition to the minimum
    required for delivery.

    As an example, when one sends a message to someone for the first
    time, he may include many items to aid in identifying the correct
    recipient.  However, once he gets a reply to this message, the reply
    will contain an Address (as opposed to Mailbox) which may be used
    from then on.

      A mailbox is a property list.  A mailbox might contain the
      following <name,value> pairs:

        name    description
        ----    -----------
        MPM     mpm-identifier
        NET     network name
        HOST    host name
        PORT    address of MPM within the host
        USER    user name (computer account name)
        PERSON  the real name of a person
        GROUP   document distribution group
        ORG     organization name
        CITY    city
        STATE   state
        COUNTRY country
        ZIP     zip code
        PHONE   phone number

    The minimum mail box is an Address or a Distribution Group.

  Message-ID

    The message identifier of this message.  This is not related to the
    MPM message identification, but is a UIP long term document
    identifier.  Represented by a text element.



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  MPM-Identifier

    The internetwork address of an MPM.  This may be the ARPA Internet
    Address or an X.121 Public Data Network Address [23].  The
    mpm-identifier is a property list which has one <name,value> pair.
    This unusual structure is used so that it will be easy to determine
    the type of address used.

  Net

    A network name.  Represented by a name element.

  NLS Block

    The information in an NLS node.  Represented by a property list.

  NLS Node

    An NLS block and substructure.  Represented by a property list.

  NLS Substructure

    A list of NLS nodes.  Represented by a list.

  Org

    An organization name.  Represented by a name element.

  Paragraph

    A paragraph of text.  Represented by a text element.

  Parcel

    The basic unit of voice data.  Represented by a bitstr element.

  Person

    The real name of a person.  Represented by a name element.

  Password

    A password.  Represented by a name element.

  Phone

    A phone number.  Represented by a name element.



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  Pointer

    A pointer to information stored outside this data structure.  A
    property list containing the information necessary to locate the
    external data, the information necessary to gain access to the
    external data, and the information necessary to apply the correct
    interpretation to the external data.  For example, this might
    include:

      name       description
      ----       -----------
      NET        network name
      HOST       host name
      FILE       file name
      USER       user name (computer account name)
      PASSWORD   password
      ACCOUNT    account
      FORMAT     format

  Port

    The address of MPM within the host.  Represented by a name element.

  Presentation Descriptor

    A property list of <name,value> pairs, where the name is an order
    indicator, and the value is a presentation element.  The order
    indicators are SEQUENTIAL, SIMULTANEOUS, and INDEPENDENT.

  Presentation Element

    A property list of media structures.

  Protocol

    The name of the coding scheme used for a medium.  Represented by a
    name element.

  References

    The message identifiers of other messages.  Represented by a list of
    text elements.

  Reply-To

    A list of mailboxes.  Sometimes it will be desired to direct the
    replies of a message to some address other than the from or the
    sender.  In such a case the reply-to object can be used.


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  R 450 Block

    The unit of Rapicom 450 data (585 bits).  Represented by a bitstr
    element.

  Sender

    A mailbox.  The sender will contain the address of the individual
    who sent the message.  In some cases this is NOT the same as the
    author of the message.  Under such a condition, the author should be
    specified in the from object.

  SID

    An NLS statement indetifier.  Represented by a integer element.

  State

    A state name.  Represented by a name element.

  Subject

    The subject of the message.  Represented by a text element.

  Text Structure

    A text data structure.  Represented by a property list.

  To

    A list of mailboxes.  To identifies the addressees of the message.

  User

    A user name (computer account name).  Represented by a name element.

  Version

    A version number.  Represented by a index element.

  Vocoder

    A vocoder name.  Represented by a name element.

  Voice Structure

    A voice data structure.  Represented by a property list.



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  X121 Address

    This identifies a host in the Public Data Network environment.  When
    used as a part of identifier, it identifies the originating host of
    a message.  The X121 address is a sequence of up to 14 digits [23].
    For use in this format the X121 address is represented in decimal
    digits.

  ZIP

    A zip code.  Represented by a name element.

2.3.  Body Structures

  2.3.1.  Simple Elements

    The body could simply be a single data element.  For example a
    single text element can represent a lengthy character string.

      <body> := TEXT

      or

      text:"this is the actual text of the body"

  2.3.2.  Structured Text

    The body could be thought of as paragraphs, where each paragraph is
    represented by a text element.  The paragraphs are then the elements
    of a list.

      <body> := LIST (<paragraph>, <paragraph>, ...)

        <paragraph> := TEXT

      or

      list:(text:"paragraph one", text:"paragraph two", ...)

  2.3.3.  NLS File Example

    It is possible to represent the data from NLS files in this format.
    NLS is a large multipurpose system which operates on structured data
    files.  The files are tree structured, and there is data associated
    with each node of the tree.  There are several fields associated
    with each node as well.




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    An NLS file is:

      proplist(                                                     file
        name:"FILENAME", name:<file>                        name of file
        name:"CREATION-DATE", name:<date>         creation date and time
        name:"VERSION", index:<version>              file version number
        name:"SID-COUNT", integer<count>               current SID count
        name:"LAST-WRITER", name:<ident>             last writer of file
        name:"OWNER", name:<ident>                         owner of file
        name:"LAST-WRITE-TIME", name:<date>     last write date and time
        name:"LEFT-NAME-DELIM-DEFAULT", name:<c>            default name
        name:"RIGHT-NAME-DELIM-DEFAULT", name:<c>             delimiters
        name:"SUBSTRUCTURE", <nls-substructure>             substructure
      )endlist

    An NLS substructure is:

      list:(                                                substructure
        <nls-node>                                 node is defined below
          .
          .
          .
      )endlist

    An NLS node is:

      proplist:(                                                    node
        name:"BLOCK", <nls-block>                    block defined below
        name:"SUBSTRUCTURE", <nls-substructure>             substructure
      )endlist

    An NLS block is:

      proplist:(                                                   block
        name:"LEFT-NAME-DELIM", name:<c>             left name delimiter
        name:"RIGHT-NAME-DELIM", name:<c>           right name delimiter
        name:"SID", integer:<sid>                             SID number
        name:"CREATOR", name:<ident>                   statement creator
        name:"CREATION-TIME", name:<date>         creation date and time
        name:"DATA", <data>                           data defined below
      )endlist









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    NLS data is: