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The sixth edition of the IPC
World Patent Information, Vol. 17, No. 1, pp. 5-8, 1995 Elsevier Science Ltd Copyright 0 1995 CEC/WIPO Printed in Great Britain. All rights reserved 0172-2190195 $9.50 + 0.00
Pergamon
01722190(94)0006Ul
The Sixth Edition of the IPC Bo Hansson, Director, International Classifications Division and Mikhail Makarov, Head of Section, International Patent Classification Section, WIPO, Geneva, Switzerland
Main changes present in the sixth edition
Summary This article describes the main features of the sixth edition of the IPC and its differences from the fifth edition. One of the latter consists of the increased number of hybrid systems whose introduction into the Classification is becoming one of the leading trends in the revision of the IPC. The decisions of the Committee of Experts of the IPC Union concerning the terminology used in the IPC, presentation of notes and application of indexing schemes are also given. Finally, the future development of the IPC is considered.
Four new subclasses have been introduced in the IPC. Two of them represent classification schemes, namely B 09 C (“Reclamation of contaminated soil”), covering mechanical, chemical and microbiological processes for the reclamation of soil and G 06 T (“Image data processing or generation, in general”), covering subject matter mainly extracted from subclass G 06 F. The other two are separate indexing schemes. These are C 07 M (“Indexing scheme associated with subclasses C 07 B to C 07 K, relating to specific properties of organic compounds”) and C 22 K (“Indexing scheme associated with subclasses C 21 D, C 22 C or C 22 F, relating to changing the physical characteristics of alloys”). The latter subclass represents the first case in the IPC where an indexing scheme introduced in one class is also associated with another class. These four new subclasses have increased the number of subclasses in the IPC to 624.
Introduction On January 1, 1995, the sixth edition of the IPC entered into use. This new edition is the result of the five-year revision of the fifth edition, carried out by the Working Group on Search Information of the WIPO Permanent Committee on Industrial Property Information (PCIPI), which is responsible for the revision, and subsequently reviewed by the IPC Committee of Experts. The periodical revision of the Classification is made in order to improve the system and to take account of technical developments. This means that the structure of the Classification depends, in an indirect way, on the progress of technology and, as technical progress is inevitable, the IPC must continue to be revised in order to satisfy its purpose of serving as a search tool for the retrieval of patent documents, as an instrument for the orderly arrangement of patent documents and for other purposes.
The substantial changes appearing in the sixth edition of the IPC concern all eight sections, but to a differing extent. Sections B, C, F G and H have undergone many substantial changes, whereas Sections A, D and E have been changed considerably less. This fact is linked, of course, with the different rate of development in the respective technical fields. The major part of the substantial changes relates to the introduction of further detailed subdivisions in existing main groups, sometimes together with the creation of new main groups. These amendments are typical for all sections of the IPC. Less widespread are the partial changes of the structure of subclasses, connected with the deletion of some main groups and consolidation of their subject matter in new main groups, often subdivided in more depth. This type of change, intended to increase the efficiency of searching similar subject matter, can be noted in Sections A, C, E, F and H. Finally, only one subclass, E 01 D (“Bridges”), has undergone almost a complete rearrangement of its structure, consisting of the change in the classification basis from materials of bridges to their constructional or functional characteristics. That there was only one case of complete restructuring of a subclass shows that the structure of the IPC on the whole is well
In the course of revision of the fifth edition of the IPC, changes have been made to a major part of its areas. However, substantial changes, such as the creation of new subclasses, considerable amendments to existing subclasses - including the creation of new main groups therein and the introduction of indexing schemes have affected only a limited number of IPC areas. In other areas, the amendments are of an editorial character and consist of introducing new references, correcting inaccuracies and clarifying wordings. The substantial changes (excluding the introduction of indexing schemes, which is discussed in a separate part of this article) are summarized below. 5
B. Hansson and M Makarov
6
established at present and is fit even for future technical developments.
F 16 D “Couplings clutches; brakes”
In order to give an overview of the distribution of the main changes among different areas in the IPC, a list is given below of the 23 most revised subclasses (only subclasses where at least two main groups have undergone substantial changes are included):
F 16 F “Springs; shock-absorbers; damping vibration”
A 61 B “Diagnosis; surgery; identification” A 61 K “Preparations toilet purposes”
for medical, dental, or
A 61 M “Devices for introducing media into, or onto, the body; devices for transducing body media or for taking media from the body; devices for producing or ending sleep or stupor” B 01 J “Chemical or physical processes, e.g. their relevant catalysis, colloid chemistry; apparatus”
for transmitting
rotation;
means for
G 01 R “Measuring electric variables; measuring magnetic variables” H 01 F “Magnets; inductances; transformers; selection of materials for their magnetic properties” H 01 G “Capacitors; capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices of the electrolytic type” H 01 L “Semiconductor devices; electric solid state devices not otherwise provided for” H 02 P “Control or regulation of electric motors, generators, or dynamo-electric converters; controlling transformers, reactors or choke coils”
B 21 B “Rolling of metal” H 04 N “Pictorial communication, e.g. television”. B 29 C “Shaping or joining of plastics; shaping of substances in a plastic state, in general; after-treatment of the shaped products, e.g. repairing” B 65 D “Containers articles or materials, boxes, cans, cartons, hoppers, forwarding closures, or fittings ments; packages” C 07 D “Heterocyclic
for storage or transport of e.g. bags, barrels, bottles, crates, drums, jars, tanks, containers; accessories, therefor; packaging ele-
The introduction of hybrid systems in the IPC has continued. As mentioned above, two subclasses, C 07 M and C 22 K, designed for indexing only, have been created. The scope of the existing subclass B 29 K, used for indexing only, has been significantly broadened by the inclusion of indexing terms relating to compositions for reinforcements, for filters and for preformed parts, used in the working of plastics.
compounds”
C 07 K “Peptides” C 12 C “Brewing of beer” C 12 H “Pasteurisation, sterilisation, preservation, purification, clarification, ageing of alcoholic beverages or removal of alcohol therefrom” E 01 D “Bridges” E 01 F “Additional work, such as equipping roads or the construction of platforms, helicopter landing stages, signs, snow fences, or the like” F 04 B “Positive liquids; pumps”
Hybrid systems
displacement
machines
for
F 15 B “Systems acting by means of fluids in general; fluid-pressure actuators, e.g. servomotors; details of fluid-pressure systems, not otherwise provided for”
Separate indexing schemes have been introduced in 19 subclasses belonging to all sections of the IPC, except Section D. The greatest number of such subclasses, seven, is to be found in Section B. In three subclasses, B 01 J, C 04 B and F 16 H, some entries, which have been used for classification purposes only, have been converted into doublepurpose entries and will also be used for indexing in the sixth edition of the IPC. The majority of the new hybrid systems are simple schemes intended for indexing only the most significant features of the respective subject matter. However, a few of them have a very detailed multifacet elaboration and are approaching the structure of deep indexing systems that the concept of hybrid systems in the IPC did not originally include. Such as, for example, indexing scheme B 01 D lll:OO-187:00, associated with group B 01 D 53/34 (“Chemical or biological purification of waste gases”), which allows indexing of the reactants used for the chemical purification, the catalysts, the type of treatment and the components removed.
The Sixth Edition of the IPC
Compared with the fifth edition of the IPC, the number of subclasses having separate indexing schemes has almost doubled and totals 34 in the sixth edition. The introduction of hybrid systems, mainly in the form of separate indexing schemes, has become one of the leading trends in the revision of the IPC and takes second place behind the introduction of further detailed subdivisions in existing classification schemes. Often, these two types of revision are made in combination. Hybrid systems exist now in all eight sections of the IPC, with most of them in Sections B and C. However, the number of classification subclasses where indexing is possible is very limited and represents only 70 out of 618 classification subclasses in the sixth edition of the IPC. This shows that the IPC is still far from becoming a multifacet classification system, fully suitable for computerized search.
Changes of a general nature in the sixth edition Besides the revision in particular technical fields, the PCIPI Working Group on Search Information and the IPC Committee of Experts prepared, to the fifth subsequently adopted, amendments edition, which concern the IPC as a whole. These modifications relate to the terminology used in the IPC, the presentation of notes and the application of indexing schemes. Thus, the expression “per se”, used widely in the IPC for distinguishing an item of subject matter itself from a combination of which that item is a part, has been reviewed throughout the IPC and in many cases its use has been corrected. The other example is the term “invention”. Since the IPC is intended for the classification not only of inventions but also, for example, of applications, it has been decided that the term “invention” could be misleading to the user of the IPC. Consequently, that term has been deleted from the notes where it occurred. However, it has been maintained in the text of the Guide to the IPC as it is unavoidable when explaining principles of the Classification. In order to facilitate the classifying of technical subjects of a general character and technical subjects specially adapted to a particular use, which is the most difficult problem for the Classification, work has been continuing on the introduction of references, in function-oriented places in the IPC, to relevant application places. Detailed lists of such references have been inserted in subclass G 05 D (“Systems for controlling or regulating non-electric variables”) and G 05 G (“Control devices or systems insofar as characterized by mechanical features only”). The task of introducing references in function-oriented places will also continue in the next revision period.
7
Several changes have been made in the presentation of hybrid systems in the IPC. Following the conclusion reached at the fourth Advanced IPC Seminar, held in Munich in 1989, that doublepurpose entries in the IPC, i.e. the entries which can be used both for classifying and indexing purposes, could be confusing for the user, those entries have been checked and some of them, considered unsuitable or unnecessary for indexing, have been excluded from indexing use. These are mainly entries relating to processes or apparatus in chemical areas of the IPC. As for the separate indexing schedules in the IPC, notes relating to subclasses used for indexing only have been standardized. Important decisions, influenced to a significant degree by the deliberations at the above-mentioned Advanced IPC Seminar, have been made with respect to the elaboration of indexing schemes. The Committee of Experts of the IPC Union has agreed that, whenever possible, the layout of the indexing schemes should be hierarchical, facilitating their presentation, and the elaboration of the schemes should be such as to allow truncation of indexing codes when carrying out database searching. Thus, indexing schemes, like classification schemes, basically have a hierarchical structure. However, they differ from the latter in the use of hierarchically higher groups. Whereas in a classification scheme a hierarchically higher group may cover subject matter classifiable in more than one of its subdivisions, in an indexing scheme the hierarchically higher group is only to be used in a residual manner, i.e. to record a specific feature not provided for in any of its subdivisions. When indexing two or more elements of information about a technical subject, which are covered by two or more indexing codes at the same level of indentation, all of those indexing codes should be allotted and not the hierarchically higher code. The structure of indexing schemes has a direct bearing on the application of indexing codes. It has been decided that indexing codes should be applied in a nondiscretionary manner, which means that all indexing codes identifying elements of information about a technical subject already classified as such should be allotted, thereby avoiding any judgement by the person indexing on whether or not to allot a particular indexing code, when the elements of information are present. The main purpose of introducing the principle of nondiscretionary indexing is to ensure consistency in the application of indexing codes, which means that the searcher should be able to rely on the indexing codes allotted. This principle will require special care when elaborating indexing schemes in order to include all technical terms that are needed, as well as specific terms with an exact meaning. Departure from nondiscretionary indexing is possible in exceptional circumstances only, for example, when such indexing
8
B. Hansson and M. Makarov
of “Markush”-type formulae would result in an unjustified number of indexing codes having to be applied. The changes in the philosophy of elaboration and application of indexing schemes are reflected in the Guide to the IPC, of which Chapter IV (“Hybrid Systems”) has been substantially revised.
revision of the IPC is needed in order to enable efficient searches to be carried out and the main goal of the further development of the IPC should be to improve the IPC as a universal search tool; care should be taken that overlapping fication concepts are not created;
classi-
any indexing scheme introduced should be associated with an adequate classification scheme;
Future development
of the IPC
Hybrid systems are becoming ever more important in the IPC. However, their application, as stated in the Guide to the IPC, is nonobligatory. At its 20th session, held in 1992, the IPC Committee of Experts discussed this problem and whether to make the application of indexing codes obligatory. Various arguments for and against were expressed. In particular, it was noted that a balance should be maintained between the resources available for classifying and indexing patent documents in a reliable manner and the effectiveness of the search. On the other hand, some patent offices pointed to the fact that indexing codes could be used for representing invention information, which was an indication that classification schemes alone, at least in certain areas, were not sufficient for recording patent information. Finally, the Committee of Experts felt that the Assembly of the IPC Union was the competent body for deciding whether the application of indexing codes should become obligatory, but in view of the lack of an overwhelming majority or consensus among its members, the Committee was not in a position to make any recommendation to the Assembly. In view of its earlier recommendation that all offices issuing patent documents should also print, on those documents, nonobligatory classification symbols and nonobligatory indexing codes, the Committee of Experts noted with appreciation that 15 offices allotted the indexing codes to the patent documents they issued. This shows that many patent offices recognize the importance of the application of indexing codes, especially from the point of view of computerized searching. It is very probable that the question of making their application obligatory will be raised again in future. In respect of the further revision of the IPC, the Committee of Experts agreed on the policy statements that should form the basis for the preparation of the seventh edition of the IPC, in particular that:
revision of the IPC that would change its basic structure should not be undertaken without good reason, for example, in order to accommodate new technologies or to avoid overlaps; if existing commercial databases that are readily available can meet the search needs in a certain area of the IPC, revision of that area should not be undertaken without good reason. In recent years, criticism has been expressed by some patent offices in respect of the development of the IPC. It was argued that the revision carried out was not always strictly necessary and that, since the basic structure of the IPC had already been established, the revision should be limited to accommodating new technologies. This initiated discussions within the framework of the PCIPI, which is entrusted by the IPC Committee of Experts with the revision of the IPC. Those discussions resulted in the decision that the IPC should continue to serve as a major search tool for patent information and that its revision should be carried out in all areas where it is considered necessary from the point of view of search efficiency. However, it was recognized that the limited resources available for the revision work should be directed to those areas which are most in need of revision. Consequently, new criteria for the selection of IPC revision projects have been adopted according to which revision requests concerning substantial revision of the IPC would satisfy quantitative criteria in respect to the size and growth of the PCT minimum documentation for the IPC groups concerned. As those criteria are sufficiently rigid, they should guarantee that the revision work concentrates on actively developing technical fields. In connection with the above-mentioned discussions, the question of the length of IPC revision periods was again considered, and it was agreed that the present five-year period of the revision should be retained as the optimal compromise between the need for stability and development of the Classification. Thus, the entry into use of the seventh edition of the IPC will coincide with the beginning of the twenty-first century.
Pergamon
01722190(94)0006Ul
The Sixth Edition of the IPC Bo Hansson, Director, International Classifications Division and Mikhail Makarov, Head of Section, International Patent Classification Section, WIPO, Geneva, Switzerland
Main changes present in the sixth edition
Summary This article describes the main features of the sixth edition of the IPC and its differences from the fifth edition. One of the latter consists of the increased number of hybrid systems whose introduction into the Classification is becoming one of the leading trends in the revision of the IPC. The decisions of the Committee of Experts of the IPC Union concerning the terminology used in the IPC, presentation of notes and application of indexing schemes are also given. Finally, the future development of the IPC is considered.
Four new subclasses have been introduced in the IPC. Two of them represent classification schemes, namely B 09 C (“Reclamation of contaminated soil”), covering mechanical, chemical and microbiological processes for the reclamation of soil and G 06 T (“Image data processing or generation, in general”), covering subject matter mainly extracted from subclass G 06 F. The other two are separate indexing schemes. These are C 07 M (“Indexing scheme associated with subclasses C 07 B to C 07 K, relating to specific properties of organic compounds”) and C 22 K (“Indexing scheme associated with subclasses C 21 D, C 22 C or C 22 F, relating to changing the physical characteristics of alloys”). The latter subclass represents the first case in the IPC where an indexing scheme introduced in one class is also associated with another class. These four new subclasses have increased the number of subclasses in the IPC to 624.
Introduction On January 1, 1995, the sixth edition of the IPC entered into use. This new edition is the result of the five-year revision of the fifth edition, carried out by the Working Group on Search Information of the WIPO Permanent Committee on Industrial Property Information (PCIPI), which is responsible for the revision, and subsequently reviewed by the IPC Committee of Experts. The periodical revision of the Classification is made in order to improve the system and to take account of technical developments. This means that the structure of the Classification depends, in an indirect way, on the progress of technology and, as technical progress is inevitable, the IPC must continue to be revised in order to satisfy its purpose of serving as a search tool for the retrieval of patent documents, as an instrument for the orderly arrangement of patent documents and for other purposes.
The substantial changes appearing in the sixth edition of the IPC concern all eight sections, but to a differing extent. Sections B, C, F G and H have undergone many substantial changes, whereas Sections A, D and E have been changed considerably less. This fact is linked, of course, with the different rate of development in the respective technical fields. The major part of the substantial changes relates to the introduction of further detailed subdivisions in existing main groups, sometimes together with the creation of new main groups. These amendments are typical for all sections of the IPC. Less widespread are the partial changes of the structure of subclasses, connected with the deletion of some main groups and consolidation of their subject matter in new main groups, often subdivided in more depth. This type of change, intended to increase the efficiency of searching similar subject matter, can be noted in Sections A, C, E, F and H. Finally, only one subclass, E 01 D (“Bridges”), has undergone almost a complete rearrangement of its structure, consisting of the change in the classification basis from materials of bridges to their constructional or functional characteristics. That there was only one case of complete restructuring of a subclass shows that the structure of the IPC on the whole is well
In the course of revision of the fifth edition of the IPC, changes have been made to a major part of its areas. However, substantial changes, such as the creation of new subclasses, considerable amendments to existing subclasses - including the creation of new main groups therein and the introduction of indexing schemes have affected only a limited number of IPC areas. In other areas, the amendments are of an editorial character and consist of introducing new references, correcting inaccuracies and clarifying wordings. The substantial changes (excluding the introduction of indexing schemes, which is discussed in a separate part of this article) are summarized below. 5
B. Hansson and M Makarov
6
established at present and is fit even for future technical developments.
F 16 D “Couplings clutches; brakes”
In order to give an overview of the distribution of the main changes among different areas in the IPC, a list is given below of the 23 most revised subclasses (only subclasses where at least two main groups have undergone substantial changes are included):
F 16 F “Springs; shock-absorbers; damping vibration”
A 61 B “Diagnosis; surgery; identification” A 61 K “Preparations toilet purposes”
for medical, dental, or
A 61 M “Devices for introducing media into, or onto, the body; devices for transducing body media or for taking media from the body; devices for producing or ending sleep or stupor” B 01 J “Chemical or physical processes, e.g. their relevant catalysis, colloid chemistry; apparatus”
for transmitting
rotation;
means for
G 01 R “Measuring electric variables; measuring magnetic variables” H 01 F “Magnets; inductances; transformers; selection of materials for their magnetic properties” H 01 G “Capacitors; capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices of the electrolytic type” H 01 L “Semiconductor devices; electric solid state devices not otherwise provided for” H 02 P “Control or regulation of electric motors, generators, or dynamo-electric converters; controlling transformers, reactors or choke coils”
B 21 B “Rolling of metal” H 04 N “Pictorial communication, e.g. television”. B 29 C “Shaping or joining of plastics; shaping of substances in a plastic state, in general; after-treatment of the shaped products, e.g. repairing” B 65 D “Containers articles or materials, boxes, cans, cartons, hoppers, forwarding closures, or fittings ments; packages” C 07 D “Heterocyclic
for storage or transport of e.g. bags, barrels, bottles, crates, drums, jars, tanks, containers; accessories, therefor; packaging ele-
The introduction of hybrid systems in the IPC has continued. As mentioned above, two subclasses, C 07 M and C 22 K, designed for indexing only, have been created. The scope of the existing subclass B 29 K, used for indexing only, has been significantly broadened by the inclusion of indexing terms relating to compositions for reinforcements, for filters and for preformed parts, used in the working of plastics.
compounds”
C 07 K “Peptides” C 12 C “Brewing of beer” C 12 H “Pasteurisation, sterilisation, preservation, purification, clarification, ageing of alcoholic beverages or removal of alcohol therefrom” E 01 D “Bridges” E 01 F “Additional work, such as equipping roads or the construction of platforms, helicopter landing stages, signs, snow fences, or the like” F 04 B “Positive liquids; pumps”
Hybrid systems
displacement
machines
for
F 15 B “Systems acting by means of fluids in general; fluid-pressure actuators, e.g. servomotors; details of fluid-pressure systems, not otherwise provided for”
Separate indexing schemes have been introduced in 19 subclasses belonging to all sections of the IPC, except Section D. The greatest number of such subclasses, seven, is to be found in Section B. In three subclasses, B 01 J, C 04 B and F 16 H, some entries, which have been used for classification purposes only, have been converted into doublepurpose entries and will also be used for indexing in the sixth edition of the IPC. The majority of the new hybrid systems are simple schemes intended for indexing only the most significant features of the respective subject matter. However, a few of them have a very detailed multifacet elaboration and are approaching the structure of deep indexing systems that the concept of hybrid systems in the IPC did not originally include. Such as, for example, indexing scheme B 01 D lll:OO-187:00, associated with group B 01 D 53/34 (“Chemical or biological purification of waste gases”), which allows indexing of the reactants used for the chemical purification, the catalysts, the type of treatment and the components removed.
The Sixth Edition of the IPC
Compared with the fifth edition of the IPC, the number of subclasses having separate indexing schemes has almost doubled and totals 34 in the sixth edition. The introduction of hybrid systems, mainly in the form of separate indexing schemes, has become one of the leading trends in the revision of the IPC and takes second place behind the introduction of further detailed subdivisions in existing classification schemes. Often, these two types of revision are made in combination. Hybrid systems exist now in all eight sections of the IPC, with most of them in Sections B and C. However, the number of classification subclasses where indexing is possible is very limited and represents only 70 out of 618 classification subclasses in the sixth edition of the IPC. This shows that the IPC is still far from becoming a multifacet classification system, fully suitable for computerized search.
Changes of a general nature in the sixth edition Besides the revision in particular technical fields, the PCIPI Working Group on Search Information and the IPC Committee of Experts prepared, to the fifth subsequently adopted, amendments edition, which concern the IPC as a whole. These modifications relate to the terminology used in the IPC, the presentation of notes and the application of indexing schemes. Thus, the expression “per se”, used widely in the IPC for distinguishing an item of subject matter itself from a combination of which that item is a part, has been reviewed throughout the IPC and in many cases its use has been corrected. The other example is the term “invention”. Since the IPC is intended for the classification not only of inventions but also, for example, of applications, it has been decided that the term “invention” could be misleading to the user of the IPC. Consequently, that term has been deleted from the notes where it occurred. However, it has been maintained in the text of the Guide to the IPC as it is unavoidable when explaining principles of the Classification. In order to facilitate the classifying of technical subjects of a general character and technical subjects specially adapted to a particular use, which is the most difficult problem for the Classification, work has been continuing on the introduction of references, in function-oriented places in the IPC, to relevant application places. Detailed lists of such references have been inserted in subclass G 05 D (“Systems for controlling or regulating non-electric variables”) and G 05 G (“Control devices or systems insofar as characterized by mechanical features only”). The task of introducing references in function-oriented places will also continue in the next revision period.
7
Several changes have been made in the presentation of hybrid systems in the IPC. Following the conclusion reached at the fourth Advanced IPC Seminar, held in Munich in 1989, that doublepurpose entries in the IPC, i.e. the entries which can be used both for classifying and indexing purposes, could be confusing for the user, those entries have been checked and some of them, considered unsuitable or unnecessary for indexing, have been excluded from indexing use. These are mainly entries relating to processes or apparatus in chemical areas of the IPC. As for the separate indexing schedules in the IPC, notes relating to subclasses used for indexing only have been standardized. Important decisions, influenced to a significant degree by the deliberations at the above-mentioned Advanced IPC Seminar, have been made with respect to the elaboration of indexing schemes. The Committee of Experts of the IPC Union has agreed that, whenever possible, the layout of the indexing schemes should be hierarchical, facilitating their presentation, and the elaboration of the schemes should be such as to allow truncation of indexing codes when carrying out database searching. Thus, indexing schemes, like classification schemes, basically have a hierarchical structure. However, they differ from the latter in the use of hierarchically higher groups. Whereas in a classification scheme a hierarchically higher group may cover subject matter classifiable in more than one of its subdivisions, in an indexing scheme the hierarchically higher group is only to be used in a residual manner, i.e. to record a specific feature not provided for in any of its subdivisions. When indexing two or more elements of information about a technical subject, which are covered by two or more indexing codes at the same level of indentation, all of those indexing codes should be allotted and not the hierarchically higher code. The structure of indexing schemes has a direct bearing on the application of indexing codes. It has been decided that indexing codes should be applied in a nondiscretionary manner, which means that all indexing codes identifying elements of information about a technical subject already classified as such should be allotted, thereby avoiding any judgement by the person indexing on whether or not to allot a particular indexing code, when the elements of information are present. The main purpose of introducing the principle of nondiscretionary indexing is to ensure consistency in the application of indexing codes, which means that the searcher should be able to rely on the indexing codes allotted. This principle will require special care when elaborating indexing schemes in order to include all technical terms that are needed, as well as specific terms with an exact meaning. Departure from nondiscretionary indexing is possible in exceptional circumstances only, for example, when such indexing
8
B. Hansson and M. Makarov
of “Markush”-type formulae would result in an unjustified number of indexing codes having to be applied. The changes in the philosophy of elaboration and application of indexing schemes are reflected in the Guide to the IPC, of which Chapter IV (“Hybrid Systems”) has been substantially revised.
revision of the IPC is needed in order to enable efficient searches to be carried out and the main goal of the further development of the IPC should be to improve the IPC as a universal search tool; care should be taken that overlapping fication concepts are not created;
classi-
any indexing scheme introduced should be associated with an adequate classification scheme;
Future development
of the IPC
Hybrid systems are becoming ever more important in the IPC. However, their application, as stated in the Guide to the IPC, is nonobligatory. At its 20th session, held in 1992, the IPC Committee of Experts discussed this problem and whether to make the application of indexing codes obligatory. Various arguments for and against were expressed. In particular, it was noted that a balance should be maintained between the resources available for classifying and indexing patent documents in a reliable manner and the effectiveness of the search. On the other hand, some patent offices pointed to the fact that indexing codes could be used for representing invention information, which was an indication that classification schemes alone, at least in certain areas, were not sufficient for recording patent information. Finally, the Committee of Experts felt that the Assembly of the IPC Union was the competent body for deciding whether the application of indexing codes should become obligatory, but in view of the lack of an overwhelming majority or consensus among its members, the Committee was not in a position to make any recommendation to the Assembly. In view of its earlier recommendation that all offices issuing patent documents should also print, on those documents, nonobligatory classification symbols and nonobligatory indexing codes, the Committee of Experts noted with appreciation that 15 offices allotted the indexing codes to the patent documents they issued. This shows that many patent offices recognize the importance of the application of indexing codes, especially from the point of view of computerized searching. It is very probable that the question of making their application obligatory will be raised again in future. In respect of the further revision of the IPC, the Committee of Experts agreed on the policy statements that should form the basis for the preparation of the seventh edition of the IPC, in particular that:
revision of the IPC that would change its basic structure should not be undertaken without good reason, for example, in order to accommodate new technologies or to avoid overlaps; if existing commercial databases that are readily available can meet the search needs in a certain area of the IPC, revision of that area should not be undertaken without good reason. In recent years, criticism has been expressed by some patent offices in respect of the development of the IPC. It was argued that the revision carried out was not always strictly necessary and that, since the basic structure of the IPC had already been established, the revision should be limited to accommodating new technologies. This initiated discussions within the framework of the PCIPI, which is entrusted by the IPC Committee of Experts with the revision of the IPC. Those discussions resulted in the decision that the IPC should continue to serve as a major search tool for patent information and that its revision should be carried out in all areas where it is considered necessary from the point of view of search efficiency. However, it was recognized that the limited resources available for the revision work should be directed to those areas which are most in need of revision. Consequently, new criteria for the selection of IPC revision projects have been adopted according to which revision requests concerning substantial revision of the IPC would satisfy quantitative criteria in respect to the size and growth of the PCT minimum documentation for the IPC groups concerned. As those criteria are sufficiently rigid, they should guarantee that the revision work concentrates on actively developing technical fields. In connection with the above-mentioned discussions, the question of the length of IPC revision periods was again considered, and it was agreed that the present five-year period of the revision should be retained as the optimal compromise between the need for stability and development of the Classification. Thus, the entry into use of the seventh edition of the IPC will coincide with the beginning of the twenty-first century.