CEN/TS 15844-1:2010

SLOVENSKI STANDARD
01-maj-2013
3RãWQHVWRULWYH2]QDþHYDQMHSRãWQLKSRãLOMN]LGHQWLILNDFLMVNRãWHYLONRGHO
6WUXNWXUDVSRURþLORLQELQDUQLSULND]LGHQWLILNDFLMVNLKãWHYLON
Postal services - ID-tagging of letter mail items - Part 1: ID-tag structure, message and
binary
Postalische Dienstleistungen - ID-Kennzeichnung von Briefsendungen - Teil 1: Struktur,
Nachrichten und Binärdarstellung von ID-Kennzeichen
Ta slovenski standard je istoveten z: CEN/TS 15844-1:2010
ICS:
03.240 Poštne storitve Postal services
35.040 Nabori znakov in kodiranje Character sets and
informacij information coding
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION
CEN/TS 15844-1
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
December 2010
ICS 03.240
English Version
Postal services - ID-tagging of letter mail items - Part 1: ID-tag
structure, message and binary
Traitement automatisé des envois postaux - Postalische Dienstleistungen - ID-Kennzeichnung von
Chronomarquage des envois postaux - Partie 1: Structure Briefsendungen - Teil 1: Struktur, Nachricht und
de la chronomarque, représentations sémantique et binaire Binärdarstellung von ID-Kennzeichen
This Technical Specification (CEN/TS) was approved by CEN on 1 December 2008 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15844-1:2010: E
worldwide for CEN national Members.

Contents Page
Foreword .3
Introduction .4
1 Scope .6
2 Normative references .7
3 Terms and definitions .7
4 Symbols and abbreviations . 10
5 Definition of an S18 ID-tag . 10
6 Data construct type . 11
7 Usage of ID-tags. 11
8 Logical structure . 12
9 Value Range . 14
10 Representation of S18 ID-tags in messages . 16
11 Binary representation of S18 ID-tags. 16
12 Representation of S18 ID-tags on items . 18
13 Usage constraints . 19
13.1 Allocation of domain codes . 19
13.2 Publication of issuer and domain codes . 19
13.3 Accuracy of time and date information in the ID-tag . 20
13.4 Allocation and application of ID-tags to items . 20
13.5 Read before allocation check . 21
13.6 Re-used envelopes . 21
13.7 Read after write check . 22
13.8 Referencing of ID-tagged items . 22
14 Reading and validation of ID-tags on items . 23
Bibliography . 24

Foreword
This document (CEN/TS 15844-1:2010) has been prepared by Technical Committee CEN/TC 331 “Postal
services”, the secretariat of which is held by NEN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
NOTE This document has been prepared by experts coming from CEN/TC 331 and UPU, under the framework of the
Memorandum of Understanding between the UPU and CEN.
1)
This document (CEN/TS 15844-1), is the CEN equivalent of UPU standard S18a-8. It may be amended only
after prior consultation, between CEN/TC 331 and the UPU Standards Board, in accordance with the
Memorandum of Understanding between CEN and the UPU.
2)
The UPU’s contribution to the document was made, by the UPU Standards Board and its sub-groups, in
accordance with the rules given in Part V of the "General information on UPU standards".
This document forms Part 1 of a multi-part CEN/TS 15844, Postal services — ID-tagging of letter mail items. It
provides the definition of ID-tags and specifies their general construction and representation for electronic
data interchange purposes. Their representation on items is covered by Parts 2 to 5, which define a number of
alternative printed representations.
The specification has been extensively tested and is in operational use: the BNB-62 encoding described in
CEN/TS 15844-3 has been used for many years by An Post (Ireland), Canada Post and USPS, whilst the
more recently specified BNB-78 encoding described in Part 2 has been operationally implemented by
Australia Post, Correios de Portugal, Correos y Telégrafos (Spain), Guernsey Post, Isle of Man Post,
Singapore Post and Swiss Post. The 4-state encoding specification, defined in Parts 4 for flats and 5 for small
letters, has been implemented by Belgian Post, Correos (Spain), Swiss Post and USPS for flats and by
Belgian Post for small letters.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Croatia, Cyprus,
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

1)
The Universal Postal Union (UPU) is the specialized institution of the United Nations that regulates the universal postal service. The
postal services of its 189 member countries form the largest physical distribution network in the world. Some 5 million postal employees
working in over 660 000 post offices all over the world handle an annual total of 425 billion letters-post items in the domestic service and
almost 6,7 billion in the international service. Some 4,5 billion parcels are sent by post annually. Keeping pace with the changing
communications market, posts are increasingly using new communication and information technologies to move beyond what is
traditionally regarded as their core postal business. They are meeting higher customer expectations with an expanded range of products

and value-added services.
2)
The UPU's Standards Board develops and maintains a growing number of standards to improve the exchange of postal-related
information between posts, and promotes the compatibility of UPU and international postal initiatives. It works closely with posts,
customers, suppliers and other partners, including various international organizations. The Standards Board ensures that coherent
standards are developed in areas such as electronic data interchange (EDI), mail encoding, postal forms and meters. UPU standards are
published in accordance with the rules given in Part VII of the General information on UPU standards, which may be freely downloaded

from the UPU world-wide web site (www.upu.int).
Introduction
Many individual postal administrations have used some form of domestic ID-tagging for the support of video-
coding applications for a number of years. Typically, however, domestic ID-tags:
 are unique only within the system of an individual issuer (or even only within a single postal processing
facility);
 are applied to only a relatively small subset of items with specific characteristics, e.g. items with
addresses which cannot be interpreted by OCR means;
 are encoded on items using a non-standardised symbology and in a non-standardised location.
These characteristics limit the utility of domestic ID-tags, preventing their use for a wide range of potential
applications and, in particular, preventing their use as an effective support for the exchange of information
between organisations about mail items.
The application of a domestic ID-tag by one organisation could also interfere with the processing of the item
concerned by another, resulting either in the need for over-labelling or for manual processing of the item. For
example, if the origin post prints its domestic ID-tag in the location used by the delivery post, the latter will be
unable to apply its (different) domestic ID-tag or, if it does, will almost certainly not be able to read the result.
The impact of this issue has historically been limited both by the limited number of items to which a domestic
ID-tag is applied and by an agreement between An Post, Canada Post and USPS (three postal
administrations which make heavy use of domestic ID-tags) to base their domestic ID-tags on a common
3)
specification . It has also been limited by the fact that some postal administrations have not yet automated
cross-border mail processing. However, increasing levels of automation and the use of ID-tagging by more
and more Posts, for a wider range of applications and on an increasing proportion of items, would, in the
absence of standardisation, lead to a marked increase in its impact and in a probable longer term deterioration
in the quality of service offered to inter-administration mail.
CEN/TS 15844-1 is intended to address these limitations. It comprises a main Part 1 (this document), together
with four subsidiary parts (Part 2, 3, 4 and 5), each of which defines a specific encoding for the printing of ID-
tags on items. This part, Part 1 of CEN/TS 15844, is arranged under ten main headings:
 Definition of an S18 ID-tag: provides a precise definition of an S18 ID-tag;
 Data construct type: specifies the relationship of this standard to UPU standard S25 [4], together with the
ID-tag data construct type;
 Usage of ID-tags: provides examples of the use of ID-tags;
 Logical structure: describes the logical structure and information content of an S18 ID-tag. These are
defined separately from the physical and electronic representations so that alternative physical
representations can be defined in the future;
 Value Range: defines limitations on the values of data elements used in the logical structure definition
and describes the procedure for allocation and publication of domain codes;

3) Note that the common An Post, Canada Post and USPS specification corresponds with one of the two BNB bar code
representations of ID-tags which are defined in this standard.
NOTE Value limitations fall into two classes – general limitations, which apply to all ID-tags, and limitations which are
specific to individual representations of ID-tags in the form of bar codes. Only the former are treated here; the latter are
treated in the relevant encoding specification.
 Representation of S18 ID-tags in messages: defines the format and structure of the ID-tag when
incorporated into EDI messages or files;
 Binary representation of S18 ID-tags: defines a recommended format and structure for a binary
representation of the ID-tag for use in computer files;
 Representation of S18 ID-tags on items: to allow the association of computer data with a physical item,
the ID-tag is encoded on the item itself. This clause introduces the supported encoding symbologies and
provides reference to the relevant specifications, covered in separate parts of the standard;
 Usage constraints: defines requirements to be met during and restrictions on the allocation of ID-tags,
their application to items and their subsequent use;
 Reading and validation of ID-tags on items: describes the procedures to be followed for the reading of
ID-tags and the use to be made of the resulting information.
1 Scope
4)
This Technical Specification defines the information content, structure and possible printed representations
5)
of the S18 ID-tag . This is an identifier for individual mail items which:
 is globally unique;
 can be applied to any item which is not already ID-tagged by any postal administration (or other issuer)
which previously processed the item;
NOTE 1 The S18 ID-tag provides a standard means of ID-tagging which can be applied on a world-wide basis, allowing
inter-administration mail items to be encoded without risk of disruption of the automated system of the delivery post. It may
be applied to any size of item.
 can be read, with a high degree of reliability, by any postal handling organisation possessing appropriate
equipment.
NOTE 2 ID-tags are encoded on items using a bar code symbology. As with any other form of bar code, poor quality
printing, ink smudging, damage to the item, etc., can result in read errors. The S18 ID-tag encoding specifications
incorporate an error protection mechanism to allow detection and correction of a large proportion of such errors.
The S18 ID-tag defined in this Technical Specification may be placed on items so that, in subsequent
processing, individual items can be recognised and associated with computer-based information relating to
the item concerned.
NOTE 3 Items need not be ID-tagged if this is not required for processing purposes, though it is anticipated that the
use made of ID-tagging will increase. Examples of ID-tag applications are given in Clause 7.
Whilst being generally applicable to domestic mail, the specification has been designed to allow the encoding
of cross-border mail and to support its application in the automated processing of such mail.
NOTE 4 UPU regulations prevent the encoding of information on the bottom 15 mm strip on the front of international
letter mail. This Technical Specification has been designed to avoid the possibility of incompatibilities between ID-tag
implementations and explicitly allows and encourages the application of S18 ID-tags, in area R1, on the reverse side of
items. This will enable exchange of data about the items and use of these data for automated processing. For example,
the origin post might send an encoded or video image electronic copy of item delivery address blocks to the delivery post,
enabling the latter to more efficiently process received items. Similarly, the delivery post might return time-of-processing
data to the origin post, enabling it to monitor delivery service quality more closely.
A key purpose of the specification is to allow information about items to be exchanged between postal
handling organisations. Such exchange will take place through the electronic communication of messages
(e.g. EDI messages), or through the exchange of computer files.
NOTE 5 The detailed requirements, content and usage procedures for these messages or files are/will be defined in
other standards, which use the S18 ID-tag as the means of associating information with the item concerned.
NOTE 6 The information content of S18 ID-tags may include specification of the time at and facility or domain in which
the S18 ID-tag was applied. A receiving facility can therefore calculate the elapsed delay to which the item has been
subjected, and can relate this to expected delays between the two facilities. This allows easy measurement of transit

4) References to "this Technical Specification" should be interpreted as references to CEN/TS 15844 as a whole, not
only to Part 1.
5) Where reference is made to a form of ID-tagging which is not in accordance with this specification, the term domestic
ID-tag is used consistently throughout the text. ID-tag on its own therefore refers to the forms of ID-tagging specified in this
Technical Specification. The term S18 ID-tag is used in the text where it is desired to emphasise the fact that reference is
being made to the ID-tag specified in this Technical Specification, and not to a domestic ID-tag.
times, even in the absence of electronic data transmission. Knowledge of delays on an item-by-item and statistical level
will improve the diagnosis of problems and is expected to lead to an improvement in delivery service quality.
The specification should be applied in all cases in which ID-tags are placed in area R1 on the reverse side of
letter mail items of size up to and including C5.
NOTE 7 ID-tags encoded in area R1 are required by article RL 123 of the UPU Letter Post Regulations [2] to be
compliant with UPU standard S18 – and by this with the related CEN/TS 15844. Where ID-tags are used, and are applied
in area R1 on the reverse side of letter mail items of size up to and including C5, the application of the specification is
therefore mandatory. As a result only BNB-78 and BNB-62 ID-tags, as defined in Parts 2 and 3 of this Technical
6)
Specification, may be encoded in area R1 .
NOTE 8 The above does not limit application of the specification to items of size greater than C5. Nether does it
prevent its application in cases in which the ID-tag is printed in an area other than R1. However, whilst the application of
the specification in such cases is recommended, it is not mandatory.
Other forms of identification may be used in locations other than R1. Issuers using automated sorting systems
are, however, strongly encouraged to identify items using this Technical Specification even when the items
carry some means of identification which has been applied by another agency, outside of issuer control.
NOTE 9 Application of the specification is presently not mandatory for ID-tagging systems which use other locations,
including on the front-side of letter mail items, or which apply to other types of item, such as flats. However, future
extensions of the specification might cover these cases.
NOTE 10 It is admissible to allow customer-allocated item identifiers in the delivery address block and/or to place
identifiers in digital postage marks. Such identifiers need not (and probably should not) follow this Technical Specification,
but might be covered by separate standards.
NOTE 11 ID-tags have a potential value even where other forms of item identification are used. For example, the ID-
tagging of items which carry an indicium-based identification can be used to improve security by aiding in the detection of
duplicate indicia. The use of the S18 ID-tag should also provide an improved probability of correct processing of the item,
especially in the case of cross-border mail.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
7)
UPU Standards glossary
UPU standard S19: Encoding on Envelopes — Placement Area Definitions
NOTE It is anticipated that UPU standard S19 will be endorsed as a CEN standard in near future.
UPU standard S31: UPU Issuing Agency — Assignment of Issuer Codes
3 Terms and definitions
For the purposes of this document, the terms and definitions given in the UPU Standards glossary and the
following apply.
6) Area R1 is defined in the UPU standard S19.
7) UPU Standards are obtainable from the UPU International Bureau, whose contact details are given in the
Bibliography; the UPU Standards glossary is freely accessible on URL http://www.upu.int.
3.1
agent code
identification code, allocated by an issuer, to distinguish between agents which have been authorised by the
issuer to allocate and apply ID-tags on the issuer’s behalf
3.2
bar
(when italicised) position, in a bar-no-bar bar code, in which a bar is printed
NOTE See also space.
3.3
bar-no-bar
bar code
representation of data in the form of a sequence of printed bars and spaces of fixed width and pitch, the
presence or absence of a bar in each position indicating the value of the corresponding bit of a computer
representation of the data
NOTE In the BNB encodings specified in this Technical Specification, the presence of a bar represents a 1 bit; its
absence represents a 0 bit. However, for encoding purposes, input data values are divided into fields and converted using
a look-up table before being printed. Thus, there is no direct correspondence between a particular bar code position and
an individual bit of the input data.
3.4
domain
subset of the postal processing facilities within which ID-tags are generated by, or on behalf of, an issuer,
usually corresponding to a single large facility or to a group of facilities which are related to one another for
postal processing purposes
EXAMPLE A set of acceptance offices might form a domain together with the main processing facility which serves them.
3.5
domain code
code used, by the issuer concerned, to identify a domain; component of equipment identifier
NOTE Domains are defined, and associated with domain codes, by individual issuers in accordance with the
principles set out in this Technical Specification. The resulting domain codes, together with address details for the main
processing facility in each domain, are made available to the UPU for publication.
3.6
domestic ID-tag
form of ID-tag which conforms to a specification other than this one
3.7
domestic ID-tagging
process of allocating and applying domestic ID-tags to items
3.8
equipment identifier
unique identifier (within a defined domain) of a particular item of equipment
NOTE Used, in the context of this Technical Specification, to identify, in an ID-tag, the item of equipment which was
responsible for ID-tag allocation.
3.9
ID-tag issuer
licensed issuer responsible for the allocation of an ID-tag
3.10
ID-tag reference
reference to an item by means of its ID-tag; representation of an ID-tag value, on a physical support other
than the item itself or an attached label
3.11
ID-tagged
property of an item which carries an encoded representation of the ID-tag which has been allocated to it
3.12
ID-tagging
process of allocating and applying ID-tags to items
3.13
item number
see Clause 8
3.14
item priority
indication of the handling priority of a mailpiece, as specified in Clause 8
3.15
misread-rate
in the context of this Technical Specification, proportion of ID-tag read attempts which result in an apparently
valid ID-tag value which differs from that (if any) which was actually applied to the item concerned
NOTE 1 See the UPU Standards glossary for a more general definition.
NOTE 2 Misreads might result in processing errors if the incorrectly read value is used to determine the processing
action to be performed on the item.
3.16
read-rate
in the context of this Technical Specification, proportion of attempts to capture the ID-tag, from an ID-tagged
item, which result in the capture of the correct ID-tag value (i.e. the value of the ID-tag which was actually
applied to the item)
NOTE 1 See the UPU Standards glossary for a more general definition.
NOTE 2 The attempted capture of an ID-tag, from an item, can result in seven possible outcomes:
1) the item was not ID-tagged and no ID-tag is detected (correct outcome);
2) the item was not ID-tagged, but an apparently valid ID-tag is detected (misread);
3) the ID-tag is correctly read, without use of error correction (read);
4) the ID-tag is read correctly, but only after making use of the ID-tag error correction capability (read);
5) the ID-tag is read and (after error correction) an apparently correct, but in fact wrong, result is obtained
(misread);
6) the ID-tag cannot be read (read failure);
7) the ID-tag is not detected at all (read failure).
3.17
serial number
see Clause 8
3.18
S18 ID-tag
ID-tag which is in conformance with this Technical Specification (used in place of ID-tag alone for emphasis)
3.19
space
(when italicised) absence of a bar in a bar-no-bar code
3.20
start bar
initial bar, of a bar-no-bar code, which is always present (i.e. is a bar) to delimit the start of the bar code
3.21
stop bar
final bar, of a bar-no-bar code, which is always present (i.e. is a bar) to delimit the end of the bar code
3.22
tag-based sorting
method of sorting and/or sequencing mail items which is based on the use of an ID-tag to access processing
instructions which are stored on a computer control system
3.23
time interval
specification of the date and interval of time during which an ID-tag was allocated; see also Clause 8
3.24
tracking indicator
status indicator, within an ID-tag, which specifies the level, if any, of tracking data, concerning the item to
which the ID-tag is applied, which the ID-tag issuer wishes to receive
3.25
upper case alphanumeric
printable character taken from the set defined in ISO/IEC 16388:2007 [8], Table 1, with the exclusion of the
start and stop character
4 Symbols and abbreviations
For the purposes of this document, the symbols and abbreviations given in the UPU Standards glossary and
the following apply.
GF23: Galois Field 23
NOTE The Galois Field number, which may be a prime or an integral power of a prime, is one of the determining
characteristics of a particular implementation of Reed-Solomon error correction.
INT(x/y): integer quotient of dividing x by y
|x| : modulus m value of x, i.e. x – mINT(x/m)
m
5 Definition of an S18 ID-tag
An S18 ID-tag is a globally unique postal item identifier allocated in accordance with this Technical
Specification, a machine readable encoded representation of which is placed on the item concerned by, or on
behalf of, a mail service contractor.
NOTE It is important to note that an ID-tag – unlike possible other forms of item identification – is optimised for postal
processing use. It is allocated by a mail service contractor, encoded on the item in a postal industry specific form and is
not intended to have significance outside the postal processing system.
6 Data construct type
The ID-tag is a compound data construct which corresponds to, and is compliant with, one of the licence plate
constructs defined in UPU standard S25 [4].
7 Usage of ID-tags
An ID-tag can be used both for identifying the item to which it is applied and as an access key to computer-
based information about the item and its processing. Mail handling processes which occur after application of
the ID-tag to an item may read the ID-tag and use this to access the stored information, enabling the latter to
be used for process control purposes.
NOTE 1 This main use of ID-tags covers applications such as on- and off-line local and remote video-coding; the
processing of item address and other data whilst the item itself is being transported and the sorting of items based on
electronically stored data (tag-based sorting). Tag-based sorting is more flexible, and potentially more reliable, than
traditional route-code-based sorting.
NOTE 2 In route-code-based sorting systems, the routing of an item has to be determined at the time of application of
the routing-code and cannot be changed (e.g. if it is subsequently determined that the item should be redirected) without
over-labelling; tag-based sorting allows the routing decision to be dynamically changed at any time prior to the last sorting
or sequencing process undergone by the item. This can greatly simplify the introduction of delivery sequencing. Also, in
tag-based sorting systems, the system can retain knowledge of the relative proximity or sequence of different items in an
aggregate being forwarded for processing elsewhere. This information, if forwarded to the downstream process, can be
used to optimise sorting and to detect and remedy probable mis-sorting.
NOTE 3 In the case of inter-administration mail, the origin post is normally only able to verify that part of the address
which specifies the country or region in which delivery is to take place: only the delivery post has the address data needed
to support full address verification and the derivation of routing information. If the origin post captures an image of the item
address and forwards this to the delivery post whilst the mail is in transit, the delivery post can use the transport delay to
process the data, allowing the item to be processed more efficiently when it arrives.
ID-tags can also be used to:
 support the measurement of the transit delay, to an item, between the process in which a time-based
ID-tag was applied and any downstream process which reads the ID-tag;
NOTE 4 Direct measurement of this delay is possible only if the ID-tag incorporates its date and time of printing. Some
ID-tag formats do not include this information. In such cases, delay measurement is only possible if the date and time of
printing is associated with the ID-tag value and forwarded electronically.
NOTE 5 The ability to measure the elapsed time between ID-tagging of an item and subsequent reading of the ID-tag
permits direct assessment of a major component of quality of service, particularly in a cross-border context. Captured data
can be used directly in checking whether inter-process delays are consistent with the required quality of service for the
item and might permit remedial action to be taken if not.
 link processing records relating to the item, allowing the progress of the item through the mail handling
process to be followed electronically (tracking) and to enable the last known status of the item to be
determined (tracing);
NOTE 6 ID-tags provide a convenient method of tracking individual items through sorting processes. The supply of
tracking data back to the issuer which applied the ID-tag will provide the issuer with direct confirmation of the insertion of
inter-administration mail items into the delivery post’s process.
NOTE 7 If ID-tag based tracking information is correlated with other data, such as collection data and tracking
information about the aggregates or receptacles in which the item is transported, a complete picture of the item’s flow
through the postal process can be built up. This can be used to provide customer-oriented tracking and tracing services
provided that the item also carries a customer allocated item identifier which is read, and associated with the ID-tag, at
some point during the process.
 support the accurate collection of statistical and other information about ID-tagged items;
NOTE 8 The analysis of tracking and other process information about large numbers of ID-tagged items can be used to
draw conclusions about the volumes of mail taking different routes through the postal system; about the route-based
performance of the system and about the resulting quality of service. This can be used in diagnosing problems which lead
to delays, mis-routing and/or item loss and to improve the accuracy of data used in quality-of-service-related terminal dues
assessments.
NOTE 9 The correlation of ID-tag based tracking data with end-to-end performance data obtained on test mail which is
also ID-tagged could be used to optimise the test mail programme, in particular by eliminating the need for this to
accurately reflect mail-flows on a route by route basis. That is, the measurement of route-based delays between first
processing and final sorting or sequencing can be done using ID-tagged live mail, resulting in test mail being needed only
to assess the delay between posting and first processing and between final sorting and delivery.
 enable a distinction to be made between two or more separate items which, in other observed respects,
appear to be identical.
NOTE 10 Particularly in cases in which postage payment is evidenced through digital postage marks, ID-tag based
processing records can be used to identify the occurrence of fraudulent duplication. Similarly, in the case of postage paid
impressions, business reply and freepost, ID-tag records can be used for the accurate counting of items and to improve
associated revenue security.
8 Logical structure
This clause defines the logical structure of an S18 ID-tag; the allowed physical representations are defined in
subsequent clauses.
An S18 ID-tag comprises the following information elements:
 UPU identifier, indicating that the ID-tag is a UPU standard S24-compliant [3] data construct;
 format identifier, indicating that the data construct is an ID-tag and specifying the ID-tag version and its
form of representation on the item concerned;
 issuer code: identifying the issuer which was responsible for assignment of the ID-tag;
NOTE 1 This ensures that no two issuers will generate the same ID-tag.
NOTE 2 Issuers are allowed to license agents to issue ID-tags on their behalf. These should be distinguished by the
use of different domain and/or equipment identifiers (see below).
 equipment identifier, uniquely identifying (for the issuer concerned) the particular item of equipment
which issued the ID-tag;
NOTE 3 The equipment identifier may relate either to an id-tag allocation and printing device or to a particular mail
processing machine. For example, if a single sorting system has multiple input sections/image capture devices, each with
their own id-tag printer, it is permitted either:
 to allocate equipment identifiers to the individual printers, each then being able to use the full range of serial
numbers (see below); or
 to allocate a single equipment identifier to the mail processing system as a whole, with individual printers then
using distinct subsets of the serial number range.
NOTE 4 The use of the term "equipment identifier" should not be taken as being limited to a specific item of processing
equipment. For example, if the issuer licenses agents to issue ID-tags on its behalf, the equipment identifier could be
replaced by an agent code.
 domain code: in certain versions of the S18 ID-tag, the most significant part of the equipment identifier
specifies the allocation domain, normally corresponding to the geographic region or group of postal
processing facilities in which the equipment which issued the ID-tag is situated;
NOTE 5 The concept of domains is intended to assist postal handling organisations, and particularly delivery posts, to
determine whether an item of mail reaching them has suffered an abnormal transit delay. Particularly between countries
with several time zones and multiple international mail processing centres, the normal delay can be a function of the
geographic region or processing facility in which the mail item was first processed.
NOTE 6 The domain code allows for:
a) determination (by table look-up) of the time zone in which an ID-tag was allocated, in turn allowing calculation of the
local time;
b) determination (by table look-up) of the normal mail transit delay between the ID-tag issuing facility and a downstream
processing facility.
 item priority, indicating the processing priority of the ID-tagged mail item;
NOTE 7 Priority information can be used to determine whether the transit delay, suffered by an item, is in accord with
normal service characteristics.
 serial number: item identification value, allowing distinction to be made between items which are
ID-tagged, by the issuer, on the same equipment, at the same item priority;
NOTE 8 It is essential that each ID-tag serial number is unique, for the issuer code, priority and equipment concerned,
for a period of at least one year: the issue of duplicate ID-tag values could result in mis-processing, mis-delivery and/or
wrongful accusation of fraud.
 time interval: in certain versions of the S18 ID-tag, the most significant part of the serial number specifies
the date of and time interval within which the ID-tag was generated;
NOTE 9 Inclusion of the date and time interval of ID-tag generation supports transit time determination, as described
above. It also simplifies the assurance of uniqueness.
NOTE 10 Given the international context and the requirement to guarantee uniqueness, use of Greenwich Mean Time
(GMT) is preferred. This avoids the risk of duplication which would occur, if local time were used, when (local) time was
put back from summer-time to winter-time. Note that GMT date can differ by up to one day from the local date. For
example, an ID-tag generated at 23:00 on 27 October 1999 local time in New York would carry a GMT time and date of
04:00 on 28 October 1999.
NOTE 11 The choice of time interval depends on the particular ID-tag format being used. It represents a compromise
between clock precision, the required serial number range (see below) and the risk of generating duplicate ID-tags, e.g.
following equipment failure.
NOTE 12 Special measures are required in case of a need to adjust the clock on the equipment backwards. Corrections
should proceed only when the equipment making use of the clock is idle (see 13.3).
 item number: in serial numbers which include generation time interval, the least significant part of the
serial number which uniquely identified the item within the specified time interval;
 tracking indicator, an indication of whether tracking of the item is requested.
NOTE 13 The setting of this indicator determines whether explicit tracking of the item is requested. If tracking is
requested, equipment reading the ID-tag should record processing information about the item, so that it can be supplied
back to the issuer concerned; if not, processing information may be discarded if it is not required for local purposes.
NOTE 14 The tracking indicator should always be turned on (tracking requested) for special items (registered and
recorded delivery, etc.); it may also be turned on for other items, e.g. to allow for collection of tracking data on a selected
sample of normal items.
NOTE 15 The information to be retained for tracking purposes should include at least the date, time, location and status
of processing, in addition to the ID-tag value itself. Desirably, the number of read errors corrected by the use of the error
correction algorithm should also be recorded. Other processing data, such as destination address data or image, may also
be retained.
NOTE 16 The tracking indicator is not considered to form part of the unique item identification. That is, ID-tags allocated
to different items should differ by more than the tracking indicator alone.
9 Value Range
This clause defines the full range of supported values for each of the logical components identified in
Clause 8, Bar coded representations, defined in CEN/TS 15844-2 to CEN/TS 15844-5, impose additional
limitations on the range of values supported.
NOTE 1 For example, the BNB-78 representation, defined in CEN/TS 15844-2, allows only issuer code values NNN to
ZZZ to be represented. Issuers wishing to generate ID-tags which can be encoded using the BNB-78 representation need
to obtain an issuer code in this range.
The UPU identifier is the single character J, corresponding to the UPU's issuing agency code.
Format identifier has 16 possible values (18A-18P), of which four are assigned and the remainder are
reserved for future use. The assigned values are:
18A ID-tag which fulfils the value limitations defined in CEN/TS 15844-2 and is represented on the item
concerned by means of the BNB-78 bar code representation specified therein;
18B ID-tag which fulfils the value limitations defined in CEN/TS 15844-3 and is represented on the item
concerned by means of the BNB-62 bar code representation specified therein;
18C ID-tag which includes specification of the date and time interval of allocation, which fulfils the value
limitations defined in CEN/TS 15844-4 and CEN/TS 15844-5, and is represented on the item
concerned by means of the 4-state bar code representation specified therein;
18D ID-tag which does not include explicit specification of the date and time interval of allocation, which
fulfils the
...