Authorised reports contain judgments that have been reviewed by the Judges or Judge's Associate, prior to the publication. They are therefore considered to be accurate record of the judgment.
Unauthorised reports are a legitimate record of court decisions. In some cases, the unauthorised report may be the only source to locate certain cases, particularly matters from local courts and tribunals covering specialised areas of law.
Unreported judgments are decisions of courts that have not been published in a law report. The decision may not have been published because for a number of reasons, such as the case being too recent, the case does not add any additional authority to the body of case law or it may have been overlooked as it is considered of little significance at the time.
In Australia, if a decision appears in an authorised report series, this is the version that must be cited in student essays and scholarly publications - see Rule 2.2.2 in AGLC4.
In all Australian courts, there is a convention that the authorised report of a judgment be cited and handed up in court in preference to other versions. In a number of jurisdictions, this convention has been formalised by Practice Direction:
Not all courts have explicit practice directions on the citation of authorities – but the use of authorised reports is a preference in all courts, whether specified by Practice Direction or a matter of convention.
For Australian cases, use CASEBASE on Lexis Advance - type in the party name/s in the Case Name box - the result should show all citations, including reported, unreported and medium neutral. To check if one of the reported versions is in an authorised report series, check the list on the Australia tabs on this Research Guide.
For example: Pape v Commissioner of Taxation has the following parallel citations: (2009) 238 CLR 1; (2009) 257 ALR 1; (2009) 83 ALJR 765; (2009) 72 ATR 580; 2009 ATC 20-116;  HCA 23; BC200905831. The CLR (Commonwealth Law Reports) is the authorised report series.
The following databases list parallel citations:
At the Melbourne Law School the Australian Guide to Legal Citation 4th edition (AGLC4) is used. It contains detailed information on the correct citation style for law reports and unreported decisions from Australian and overseas jurisdictions.
For further information about accessing AGLC4 and for citation styles used in other jurisdictions and from other publishers, please refer to the Citation Guides page on the Law Library website.
Example: Pape v Commissioner of Taxation has the following parallel citations: (2009) 238 CLR 1; (2009) 257 ALR 1; (2009) 83 ALJR 765; (2009) 72 ATR 580; 2009 ATC 20-116;  HCA 23; BC200905831.
In Australia, the following citation convention applies (refer to AGLC4 Rule 2.2.2):
Note that in the Pape example given above, the order the citations appear is generally the order of citation preference. This is taken from CaseBase on Lexis Advance. Westlaw Au does not provide this type of order - so may cause confusion.
This order of preference generally applies in other jurisdictions also.
The Cardiff Index to Legal Abbreviations (open access) allows you to search for the meaning of abbreviations for English language legal publications, from the British Isles, the Commonwealth and the United States, including those covering international and comparative law. A wide selection of major foreign language law publications is also included. Publications from over 295 jurisdictions are featured in the Index.
The database mainly covers law reports and law periodicals but some other legal publications are also included. This guide can be searched by abbreviation AND full-text title.
The Monash University Legal Abbreviations Guide (open access) is useful, particularly for some Australian material not covered by Cardiff. But this guide only converts abbreviations into full text, so you cannot search the full-text title and convert it to the abbreviation.
More comprehensive than any of the above is Donald Raistrick, Index to legal citations and abbreviations (Sweet & Maxwell, 4th ed 2013). This book is in the High Use Collection in the Law Library.