Repeat Citations, Ibid and Short Titles
How to cite a source the second time, when Ibid applies, and how to define and use short titles.
Once you’ve cited a source in full, you usually don’t need to repeat all of the citation details again. AGLC4 uses two methods for later references:
Repeat citations
- Ibid, when you’re citing the source from the footnote immediately above.
- Short citations using (n), when you’re referring back to a source cited earlier in the document.
These rules are covered in AGLC4 rule 1.4.
The first time you cite a source, you provide the full citation. After that, every later reference uses either Ibid (if the source appears in the footnote immediately before) or a short citation with a cross-reference, such as (n 4).
This keeps your footnotes shorter and makes them easier to read.
Using Ibid
Ibid is short for the Latin word ibidem, meaning ‘in the same place’.
You can only use Ibid when you’re citing the same source as the immediately preceding footnote.
Same source, same pinpoint
If you’re referring to exactly the same page, section or paragraph as the previous footnote, simply write Ibid. Nothing else is needed.
Same source, different pinpoint
If you’re citing the same source but a different page or paragraph, add the new pinpoint immediately after Ibid.
Notice there is no comma after Ibid.
Introductory signals with Ibid
You can still use introductory signals such as See, Cf or But see before Ibid.
The signal only changes how the citation should be interpreted. It doesn’t change what Ibid refers to.
When can’t you use Ibid?
There are three situations where Ibid cannot be used.
1. The previous footnote contains more than one source
Because Ibid can only refer to a single source, you must instead use a short citation with (n).
2. The previous footnote includes a pinpoint, but your new citation doesn’t
If footnote 8 cites page 45 of a book and your next footnote refers to the whole book rather than page 45, you cannot write Ibid. Use a short citation with (n) instead.
3. The source isn’t in the immediately preceding footnote
Even if the same source appears only one or two footnotes earlier, Ibid only ever refers to the footnote directly above.
Using (n)
If the source you’re citing doesn’t appear in the footnote immediately before, use a shortened citation with a cross-reference.
The general format is:
Author or Short Title (n footnote number) pinpoint.
Which shortened name should you use?
The shortened name depends on the type of source.
- Books and journal articles
- The author’s surname.
- Cases
- The case name, in italics.
- Legislation
- The short title of the Act, in italics.
Multiple works by the same author
If you’ve cited more than one work by the same author, include part of the title as well so readers know which work you’re referring to.
Authors with the same surname
If two different authors share the same surname, use their full names instead of just the surname to avoid confusion.
Remember to update footnote numbers
Cross-references use footnote numbers, so if you insert or delete footnotes while editing your document, make sure you check that every (n) reference still points to the correct footnote before submitting.
Short titles
A short title is simply an abbreviated version of a source’s title that you define the first time you cite it.
You introduce the short title at the end of the first full citation by placing it in parentheses. After you’ve introduced the short title once, you can use it throughout the rest of your document.
Key points
- The first citation must always be the full citation.
- Introduce the short title once in the first citation.
- Don’t redefine the short title every time you use it.
- Cases can also be given short titles in the same way under rule 2.1.14.
Last reviewed 4 August 2026