There is often interest in how to write X.400 email
addresses on business cards. A CCITT Study Group 
has now had approved a proposal on how to do this.  
This Recommendation will be published in a few months
(fall 92). It is currently in an Annex of CCITT Study
Group I Report R 44.  I talked with the CCITT counsellor 
responsible for Study Group I and he agreed that I 
could pass on this relevant text.

Bob Shaw
Information Services Department
International Telecommunication Union
Place des Nations
1211 Geneva, Switzerland
Voice: +41 22 730 5338/5554
FAX: +41 22 730 5337
Internet: shaw@itu.arcom.ch
X.400:G=robert;S=shaw;P=itu;A=arcom;C=ch
MCI: rshaw
Compuserve: 100012,2025

Title: REPORT OF THE FINAL MEETING OF STUDY GROUP
I, GENEVA, 24 MARCH-3 APRIL 1992: DRAFT NEW AND REVISED
RECOMMENDATIONS IN THE F.400, F.500-SERIES, CURRENTLY
BEING SUBMITTED FOR APPROVAL BY MEANS OF CCITT RESOLU-
TION NO. 2.

This text is extracted from Annex B of CCITT Study Group
I Report R 44.  

                        ANNEX B
                           
    Representation of O/R addresses for human usage
                           
                           
  (This Annex does not form an integral part of this
                    Recommendation)
                           
  (This Annex is aligned with ISO/IEC 10021-2, Annex
  F(DAM) and is referenced forward in Recommendation
                        X.402)

B.1  Purpose

An O/R address consists of a set of attribute values
taken from a total of 31 possible attributes. In order
to represent visually an address to a human user, and
to enable the user to enter the address into a user
interface, each attribute value needs to be associated
with the correct attribute type. Many of the full
attribute types given in CCITT Rec. X.402 are too long
for convenient usage on paper or a screen. There is a
need for a format which allows attributes to be
represented concisely, e.g. on a business card.

This Annex specifies how addresses can be expressed
concisely using labels to represent the attribute
types. There are three categories of attributes: those
standard mnemonic attributes which are most likely to
be found in O/R addresses represented for human
exchange (e.g. on business cards), those used in
physical delivery addresses, and other specialized
attributes (including domain defined attributes). In
order to provide a format which is as concise as
possible, many of the labels are single characters.
This also makes them less language dependent.

Clause B.3 specifies the format for the representation
of addresses, and clause B.4 specifies the
characteristics necessary for user interfaces which
are intended to be used in conjunction with this
format.

B.2  Scope

A labelled format for the communication of O/R
addresses to human users is specified. The format
consists of a set of pairs of labels and attribute-
values. The characteristics of a user interface which
are necessary to accept addresses given in this format
are also specified.

In addition a self-explanatory format suitable for use
where there is more space, e.g. in printed material
and in the user interface, is specified.

B.3  Format

B.3.1   General

Some systems are capable of accepting messages when
certain optional attributes of the recipient's O/R
address (e.g. OUs) are omitted by the originator. In
these circumstances it is normally preferable to use
the shortest acceptable form of the address when
representing the address for human usage.

Note 1 - OUs should only be used to disambiguate users
with the same Surname if this cannot be achieved by
the use of other name attributes (Given Name,
Initials, or Generation Qualifier). The use of
additional OUs for this purpose has the disadvantage
that the user's O/R name will change if the naming of
the OUs changes, or if the user moves to a different
OU.

Where national usage permits a single space value for
the ADMD in an address, this may be represented in the
address either by omitting the ADMD attribute, or
showing the ADMD attribute with no value or the value
of a space.

Note 2 - When sending messages internationally, there
may be difficulties in reaching a recipient if a
single space ADMD name is specified.

If the attributes of an O/R address include characters
from an extended character set, human users who do not
normally use the same extended character set may have
difficulty representing the O/R address or entering it
into their messaging system.

B.3.2   Labelled format

B.3.2.1    Syntax

O/R addresses in labelled format consist of delimited
pairs of labels and values in the syntax
<label>"="<value>. The labels for each attribute are
specified in Tables B.1, B.2 and B.3. (The physical
delivery attributes in Table B.2 are included for
completeness.) The label and its value are either
separated by the character "=", or by the space
between two columns in a table. The value is supplied
by the human user and is case insensitive.

If label/value pairs appear in sequence on a line,
they are separated by delimiters. The delimiter
character may be either ";" or "/", but only one of
these can be used in one O/R address. If the value of
any attribute contains the delimiter character, this
is represented by a pair of delimiter characters. If
the value of the first attribute contains the
alternate delimiter character, this is represented by
a pair of alternate delimiter characters.

Note - When the label-value pairs appear in sequence
on a line, the use of upper case for labels and lower
case for the values makes the format clearer for the
user.

If an identifier is required to preface a labelled
address, it is recommended that "X.400" is used.

If an address is entirely composed of attributes
contained in Table B.1, it is recommended that the
sequence of attributes in the address is that given in
Table B.1. If this sequence is incompatible with
normal cultural conventions, an alternative sequence
may be adopted for representations of addresses which
are primarily intended for use within that culture.

                       TABLE B.1
   Standard attributes of the mnemonic address form
                                                    
Attribute type                 Abbreviation       Label
                                            (where necessary)
                                                    
Given name                     Given name          G
                                                    
Initials                       Initials            I
                                                    
Surname                        Surname             S
                                                    
Generation Qualifier           Generation          Q
                                                    
Common Name                    Common Name         CN
                                                    
Organization                   Organization        O
                                                    
Organizational Unit 1          Org.Unit.1         OU1
                                                    
Organizational Unit 2          Org.Unit.2         OU2
                                                    
Organizational Unit 3          Org.Unit.3         OU3
                                                    
Organizational Unit 4          Org.Unit.4         OU4
                                                    
Private Management Domain Name PRMD                P
                                                    
Administration Management      ADMD                A
Domain Name
                                                    
Country                        Country             C
                           

                       TABLE B.2
             Physical delivery attributes
                                                       
Physical Delivery Personal Name  PD-PN                 PD-PN
                                                       
Extension of Postal O/R Address  PD-ext.address        PD-EA
Components
                                                       
Extension of Physical Delivery   PD-ext.address        PD-ED
Address Components
                                                       
Physical Delivery Office Number  PD-office number      PD-OFN
                                                       
Physical Delivery Office Name    PD-office             PD-OF
Physical Delivery Organization                         
Name                             PD-O                  PD-O
                                                       
Street Address                   PD-street             PD-S
                                                       
Unformatted Postal Address       PD-address            PD-A
                                                       
Unique Postal Name               PD-unique             PD-U
                                                       
Local Postal Attributes          PD-local              PD-L
                                                       
Postal Restante Address          PD-restante           PD-R
                                                       
Post Office Box Address          PD-box                PD-B
                                                       
Postal Code                      PD-code               PD-PC
                                                       
Physical Delivery Service Name   PD-service            PD-SN
                                                       
Physical Delivery Country Name   PD-C                  PD-C
                           

                       Table B.3
                   Other attributes
                                            
X.121 Network Address       X.121         X.121
                                            
E.164 Network Address       E.164         E.164
                                            
PSAP Network Address         PSAP         PSAP
                                            
User Agent Numeric ID        N-ID         N-ID
                                            
Terminal Identifier          T-ID         T-ID
                                            
Terminal Type                T-TY         T-TY
                                            
Domain Defined            DDA:<type>    DDA:<type>
Attribute

where the notation <type> identifies the type of
domain defined attribute.

EXAMPLE 

X.400: G=john; S=smith; O=a bank ltd;P=abl; A=snomail; C=aq

This address may also be laid out as a table:
G John
S Smith
O A Bank Ltd
P ABL
A Snomail
C AQ
                           
B.3.2.2    Terminal type

There are currently six terminal types, and if
international consistency is required the following
specific abbreviations should be used to represent the
values for these types: tlx, ttx, g3fax, g4fax, ia5
and vtx.
                           
B.3.2.3    Domain defined attribute

The label for a DDA consists of "DDA:" followed by the
DDA type. If an address includes more than one DDA of
the same type, it is assumed that the DDAs are
intended to be processed in the sequence in which they
are represented.

EXAMPLE

DDA:RFC-822 = fred(a)widget.co.uk;O=gateway;P = abc;C = gb

If the <type> of a DDA type includes the character
"=", it is represented by "=".
                           
B.3.3   Self-explanatory format

The self-explanatory format may be used when space is
available. It consists of a list of the attribute
types, either in full or abbreviated. The attribute
types or abbreviations may be in any language, but
each attribute type or abbreviation in Table F.1 is
followed by the specified label. If English language
abbreviations are used, they should be those given in

Tables B.1, B.2 and B.3.

If an address is entirely composed of attributes
contained in Table B.1, it is recommended that the
sequence of attributes in the address is that given in

Table B.1. If this sequence is incompatible with
normal cultural conventions, an alternative sequence
may be adopted for representations of addresses which
are primarily intended for use within that culture.

EXAMPLE 1 - Using attribute types in Norwegian language

           Fornavn (G)                Per
           Etternavn (S)              Hansen
           Organisasjon (O)           Teledir
           Organisasjonsenhet (OU1)   Forskning
           Privat domene (P)          Tele
           Administrasjonsdomene (A)  Telemax
           Land (C)                   NO

EXAMPLE 2 - Using attribute types and abbreviations in English language

           Given name (G)             John
           Surname (S)                Smith
           Organization (O)           A Bank Ltd
           Org. Unit (OU1)            IT Dept
           Org. Unit (OU2)            MSG Group
           PRMD (P)                   ABL
           ADMD (A)                   Snomail
           Country (C)                AQ
                           
B.4  User interface

This clause specifies the characteristics of a user
interface which are necessary to enable a user to
input O/R addresses represented in either of the
formats specified in clause B.3.

It is necessary for the user interface to be able to
accept any valid combination of attributes from Tables
B.1, B.2 and B.3.

If the user interface lists the attributes given in
Table B.1, it is recommended that either the sequence
used in Table B.1 should be used, or if this sequence
is incompatible with normal cultural conventions, the
alternative sequence adopted within a particular
culture.

If the user omits the ADMD attribute, or omits the
value for the ADMD attribute, the ADMD value to be
used is a single space provided that the country
specified in the O/R address permits use of the single
space value for ADMDs.

Where an interface accepts an O/R address as a single
string (e.g. in a command line interface), it is
necessary to accept any valid labelled format address
allowing the user to enter either delimiter. The
interface should not require the attributes to be
specified in any particular order.

Note - For some existing command line interfaces it
may be necessary to enclose the whole labelled format
address in quotes.

If any other type of interface is provided (e.g. a
prompting or form-fill interface), it is necessary to
provide a means which enables the user to easily
associate the identity of each attribute with the
labels specified in Tables B.1, B.2 and B.3.

NOTES

1    One way to associate the identity of each
attribute with the labels is to follow the name or
abbreviation for each attribute with the label in
brackets, for example:

Given name (G)
Initials (I)
Surname (S)
Generation Qualifier (Q)
Common Name (CN)
Organization (O)
Organizational Unit 1 (OU1)
Organizational Unit 2 (OU2)
Organizational Unit 3 (OU3)
Organizational Unit 4 (OU4)
Private Management Domain Name (P)
Administration Management Domain Name (A)
Country (C)

2    Many users may have difficulty copying an address
presented as a table (either in labelled or self-
explanatory format) into a command line interface
which uses delimiters.

3    For form-fill style interfaces, user performance
will be optimized when the interface most closely
resembles the format of the supplied address with the
same sequence of attributes using the same attribute
types or labels.

EXAMPLES OF APPLICATION
1    The Norwegian user of a command line interface
receives a business card containing the following O/R
address:

G=john; S=smith; O=a bank ltd; P=abl; A=snomail; C=aq

The command line interface enables the user to type in
the address exactly as presented on the card.

2    The Norwegian user of a form fill interface
receives the same business card. The form on the
screen includes the following field names:

Fornavn (G)
Etternavn (S)
Organisasjon (O)
Privat domene (P)
Administrasjonsdomene (A)
Land (C)

The user is able to fill in the form by associating
the single letter labels on the business card with the
same labels in brackets after the Norwegian names of
the attributes on the screen. (For form fill input the
delimiters are not used.)

3    The English speaking user of a command line
interface receives a document quoting the following
O/R address:

          Fornavn (G)                  Per
          Etternavn (S)                Hansen
          Organisasjon (O)             Teledir
          Organisasjonsenhet (OUI)     Forskning
          Privat domene (P)            Tele
          Administrasjonsdomene (A)    Telemax
          Land (C)                     NO

The user has been trained how to use the interface,
and can correctly enter the address either as:
g=per;s=hansen;o=teledir;oul=forskning;p=tele;a=telemax;c=no

                        or as:
g=per/s=hansen/o=teledir/oul=forskning/p=tele/a=telemax/c=no

(The input supplied by the human user is not case sensitive.)