Proposal for participation in the One-Day Workshop on Hypertext Systems and Version Support

John Robertson
University of Technology
Sydney Australia

Frank Merrick
Australian Taxation Office


The Australian Taxation Office (ATO) has been involved in development of a large online hypertext legal information systems since 1990. This system, the Information and Research System (IRIS) is used for research purposes by tax experts within the ATO. The system is currently 263 megabytes large and it is anticipated that it will reach a gigabyte in size within the next couple of years. The ATO has made a large commitment to this project, spending several million dollars on development so far. The hypertext database contains Acts of Parliament ("Acts"), Court Cases, Taxation Office Rulings and Determinations, Explanatory Memoranda to supplement the legislation, Butterworths and CCH commentary, and a history of Australian tax legislation.

Recently, the Australian government has directed the Australian Taxation Office to rewrite the tax laws, making them more intelligible to the average tax payer and to provide online access to this new system. The new system will contain hypertext links. This project is named "The Law Improvement Project".

Versioning is proving to be both a critical and troublesome problem for the IRIS and the Law Improvement Project. Both projects must devise a methodology and implement a practical solution to meet their versioning requirements.

The ATO Versioning Problem

Tax law is constantly changing. Through Acts, Court Ruling, and changes to internal ATO guide-lines, both the tax laws and the way they are applied are altered. Subject to some minor exceptions Acts are the only modifiable document type in each project's document set. Court Cases, Taxation Office Rulings and Determinations, Explanatory Memoranda, use riders to update changes. Therefore, the document type that is the most problematic for the ATO is the Act.

If a new Act supersedes a portion of an existing Act, this does not mean that the replaced portion of the preceding Act no longer has legal force. Legal issues that arise can be dependent upon a version of an Act other than the current one. Therefore it is necessary to maintain each version of all Acts.

There a number of Act types the ATO must manage:

Each Act can have versioning links to/from other Acts. These versioning links have type information. There are a number of values the versioning link type can take:

For each Act, the reader must be able to identify differences between each version of the Act. For example, when reading Version 2 of Act XX ("Consolidation of Act XX of Mar. 1994)", the reader must be made aware of the existence of versions 1 and 3 (Figure 0-1). The reader should be able to browse between the relevant Amended Acts and Consolidations, through the use of links. (missing in ascii version of proposal) Figure 0-1 Version History of Act of Parliament XX

How the ATO currently manges versioning

The IRIS Project currently maintains only the latest version of each Act of Parliament. This means that when a Act is modified, the new version (consolidation) of the Act is entered into the database, and the previous version is removed.

The IRIS project maintains a history of changes to Acts of Parliament. Readers are able to determine variances between versions of the Acts with this historical database. This portion of the system is hand crafted by legal experts. There were attempts at automating the creation of historical records but this proved to be inadequate. The current authoring process is proving to be too expensive. There is need to improve the way this is done.

How the ATO would like to manage versioning

Some of the requirements established by the ATO for versioning in the new systems are:

For example, in Figure 0-2, Act 1, Section 2 has a set of semantic links or cross-references to other Acts. In Figure 0-3, Act 1, Section 2 Version 2 replaces version 1. How are the cross references to be managed? (missing in ascii version of proposal) Figure 0-2 Stage One (missing in ascii version of proposal) Figure 0-3 Stage Two