Z39.50 Maintenance Agency Terms of Reference and Procedures 1. Introduction The Z39.50 maintenance agency is responsible for the ongoing maintenance of ANSI standard Z39.50-1988. Responsibilities include: - maintenance of mailing list and registration of implementors; - coordination of modifications and enhancements, including defect corrections, changes, new services, companion specifications, and architectural enhancements; - coordination of technical reports; and - development of US position on related ISO standards. 1.1 Definitions Z39.50 Editor - The editor of Z39.50 designated by the maintenance agency, and approved by NISO. Editor - An individual, designated by NISO as the editor for a particular modification or enhancement to Z39.50. The use of the term "editor" is context specific, and may refer to "Z39.50 editor" if there is no ambiguity. Implementor - A vendor or institution who has begun implementation of Z39.50 and who registers as such with the maintenance agency. Mailing list - Z39.50 mailing list, including a directory of implementors as well as any NISO information or voting member who wishes to be included on the list. Constituent - A NISO member or implementor. 2. Editors The maintenance agency will designate an individual, with NISO concurrence, as the general editor of Z39.50, referred to as the "Z39.50 editor". In addition, NISO will designate individuals as needed as editors for various documents to be developed. The use of the term "editor" in this document is context specific, and may refer to the Z39.50 editor if there is no ambiguity. 3. Registration of Implementors The maintenance agency will maintain a Z39.50 mailing list of constituents, which will comprise implementors as well as any NISO member who wishes to be included on the list. NISO will publicize the fact to potential implementors that they might qualify as a member of the Z39.50 mailing list by providing information to the maintenance agency, indicating their intention to implement Z39.50, as well as voluntary information about their potential product. This information could include target configuration, market, and date of delivery; services, options, and features implemented; and any other pertinent information. Although each entry in the mailing list will distinguish a specific individual, membership on the mailing list will be by organization. If an individual requests to be included on the mailing list, the maintenance agency reserves the right to deny the request if his organization is already represented on the mailing list. Furthermore, the maintenance agency may deny the request if the organization is neither a NISO member nor a serious potential implementor. 4. Modifications and enhancements to Z39.50 There are six categories of modifications and enhancements to Z39.50; (1) defect corrections, (2) changes, (3) new services, (4) architectural enhancements, (5) companion specifications, and (6) technical reports. Defect corrections, changes, new services, and architectural enhancements will require amendment to the Z39.50 standard. Companion specifications will either be separate standards or addenda to the Z39.50 standard. Technical reports will be separate documents, not part of the Z39.50 standard. 4.1 Defect Corrections A defect report may be submitted by a constituent. There are five types of defects. 1. Minor editorial (mE): A typographical, spelling, or minor clerical or editorial effects which there is no urgent need to fix. These can be corrected in the next version of the standard. 2. Major editorial (ME): A clerical defect whose solution is obvious, but which should be corrected before the next version of the standard. An example (submitted from RLG) is table A7 on page 43. Its title is correct but the contents are wrong -- it repeats the Present APDU, instead of showing the Present-response APDU. 3. Minor Technical (mT): A minor defect in the protocol, whose solution is obvious, and which is not serious enough to warrant a new version of the protocol. 4. Major Technical 1 (MT1): A major defect in the protocol, whose solution is obvious, which is serious enough to warrant a new version of the protocol. 5. Major Technical 2 (MT2): A major defect in the protocol, whose solution is not necessarily obvious, which is serious enough to warrant a new version of the protocol. When a defect report is submitted, the Z39.50 editor will determine the category of defect. (If the submitter does not agree with the Z39.50 editor's determination of the category, then NISO will resolve the dispute.) If the category is mE or mT, the editor will develop and write-up a correction report to be distributed, for information only, to constituents. The correction will not actually be applied to the standard until the next version. The editor, at his discretion, may include several mE and/or mT defect reports in a single correct report. If the category is ME, the editor will develop and write up a tentative correction report, distributed to constituents. In addition, NISO will distribute the report to all NISO members, with a notis that the correction will be applied to the standard as an interim fix if there are no objections received from voting members within sixty days. If objections are received, the editor will attempt to resolve them, and niso will make the final determination. If the category is MT1 or MT2, then a new version of the protocol is necessary, which means that a new version of the standards must be balloted. The editor will distribute a report to implementors, which will include the proposed solution in the case of an MT1 defect, and will include the editors analysis of the problem, for an MT2 defect. In either cases, the report to implementors will not that no change to the protocol will take effect without re-balloting. An MT2 defect requires resolution by a NISO committee. See section 7. 4.2 Changes A "change" is a modification of the Z39.50 protocol which is not considered a defect correction or an enhancement. As an example, the parameter Element-set-name in the search request might be replaced with two slightly different but related parameters. The reason for such a change would be strictly for compatibility with the ISO Search and Retrieve protocol. A similar example would be to add record composition parameters as in the ISO standard. In order for a change to be effected, a new version of the protocol is necessary, which means that a new version of the standards must be balloted. A Change Proposal may be submitted by a NISO voting member to the maintenance agency. It will be distributed to constituents with a cover letter, soliciting comments. When a change request is submitted, the Z39.50 editor, at his discretion, may wait for a period of up to four months to accumulate other related change requests, as well as comments. It is anticipated that change request will occur infrequently, and only with compelling reason. Therefore, it is likely that change requests might be submitted from several organizations, covering the same change. Some requests might be redundant, and different requests might vary slightly, or conflict. Furthermore, some proposals may, in the opinion of the editor, be frivolous or flawed. In any of these cases, the editor will work with the submitter to attempt to resolve all of the concerns of the submitter, commentors, and the editor. If this effort is successful, the editor will request NISO to ballot a new version of the standard which includes the change proposals. Otherwise, an ad hoc committee will be appointed to resolve these issues. See section 7. 4.3 New Services The following services are explicitly listed in the foreword to Z39.50 to be considered as services to be added to the standard: - List Databases - List Access Points - Browse - Sort Result Set - Save Result Set - List elements - Define Element Set - List Element Set - List Element Sets - Concurrency control An editor will be appointed by NISO to draft changes to incorporate these services into the standard. NISO will appoint one or more ad hoc committees to consider these services, and any others which may be proposed by constituents. See section 7. 4.4 Companion Specifications Companion specifications are enhancements to Z39.50 related to conformance testing, functional use, implementation, formal or normalized specification, etc. An enhancements in this category may be progressed as a separate standard, an addendum to the Z39.50 standard, or a normative appendix, depending on practical considerations and common ANSI or ISO practice. The process by which NISO selects a companion specification to be progressed is outside the scope of the maintenance agency (however the maintenance agency may have input to this process). For each companion specifications NISO will assign an editor to draft a specification. It will be distributed to constituents, soliciting comments, with a two month comment period. If the comments can be incorporated without difficulty, the editor will do so, and if the comments indicate substantial support for the specification, then the maintenance agency will request NISO to convene an ad hoc committee to resolve the comments. See section 7. The following companion specifications have been proposed: ANS.1 abstract syntax definition, protocol implementation conformance statement (PICS) proforma, conformance test suits, registration requirements and procedures, application context definitions, data structures (attribute lists, diagnostics, report formats, query structures). 4.5 Architectural Enhancements Architectural enhancements are structural changes to the protocol which are necessary to support new features which themselves might be incorporated as companion specifications. Two examples of such features, explicitly listed in the foreword to Z39.50, are the capabilities to map (1) the protocol onto message handling services, and (2) the Init service onto the association control service. Architectural enhancements will be progresses in the same manner as companion specifications - that is, they will be assigned by NISO, an editor will be designated, there will be a comment period, a committee will be formed if necessary, and they will be balloted. 5. Technical Reports Three types of technical reports have been identified so far, to be published in conjunction with Z39.50: (1) an implementors guide, (2) Z39.50 profiles, and (3) questions and commentaries. 5.1 Implementors Guide NISO will assign an editor to draft an implementors guide to Z39.50. It will be distributed to constituents, soliciting comments, and subsequently published. 5.2 Profiles A draft Z39.50 profile may be submitted by a constituent to the maintenance agency. The Z39.50 editor will work with submitter to eliminate redundant profiles and to achieve compromise between overlapping profiles, and thereby avoid the proliferation of unnecessary profiles. The process by which profiles are to be subsequently progressed will be further developed as this area becomes more mature. 5.3 Questions and Commentaries NISO will maintain a list of questions and commentaries on Z39.50, similar to the commentaries on the OSI reference model maintained by ISO. Questions may be submitted by constituents. The Z39.50 editor will provide an interpretation and analysis of the question, if necessary and appropriate, and distribute to the mailing list, soliciting comments and proposed "answers". The editor will determine, based on comments, whether there is a consensus answer. If so, the question will be considered tentatively resolved. The question, interpretation, answer, and (possibly) a commentary will be written up for subsequent addition to the technical report "Questions and commentaries on ANSI Z39.50". Periodically, one of the ad hoc committees will consider all tentatively resolved questions for approval. Those approved will be added to that technical report. 6. US Position on Related ISO Standards NISO is responsible for the U.S. position on various ISO standards, in particular, those which are comparable to Z39.50. NISO will convene ad hoc committees to develop U.S. positions on such standards, see section 7. 7. Ad Hoc Committees In certain situations as described above, NISO will convene an ad hoc committees of experts to formulate U.S. positions, or resolve technical issues related to defects, change requests, new services, architectural enhancements, and companion specifications. NISO, at its discretion, may assign several such projects to a single ad hoc committee. The maintenance agency will coordinating the work of these committees.