The prior art base includes designs that have an earlier priority date than a registered design under examination but are published on or after the priority date of the registered design.

Designs that have an earlier priority date have precedence over later designs – even if the earlier design was not published before the priority date of the later design (s 15(2)(c)).

In these cases:

the design must be disclosed in a design application (this must be an Australian design application)
the design has an earlier priority date than the designated design (i.e. the subject design under examination)
the first time documents disclosing the design are made available for public inspection under s 60 (published on Australian Design Search) is on or after the priority date of the subject design.

Example

A potential citation was published on Australian Design Search (ADS) as a registered design on 3 April 2020, with a priority date of 10 November 2019. The design is disclosed in an Australian application.

The subject design (the design under examination) was published on ADS as a registered design on 10 March 2020, with a priority date of 1 January 2020.

The potential citation is a design disclosed in an Australian design application.
It has an earlier priority date than the subject design (10 November 2019 compared to 1 January 2020).
The first time the design was disclosed (made available for public inspection under s 60) was after the priority date of the subject design. It was made publicly available on ADS (on 3 April 2020) after the priority date of the subject design (1 January 2020).

The following should also be noted:

The earlier design is not part of the prior art base until it is published – either after registration or after s 57 publication (previous publication only option).
If the later registration is examined before the earlier design is published, a ground for revocation cannot be raised based on the earlier design. This is because:
the earlier design has not been published, and publication is required for the ground for revocation to be valid
raising the ground for revocation, and including an image of the earlier design in an examination report, would almost certainly be considered a publication of the earlier design in contravention of s 61.

Because the file of the subject design being examined is open to public inspection, a file note referring to the earlier application (and design) will also amount to publication of that earlier design – contrary to the intent of s 61. Examiners should not make any file notes that refer to unpublished potential citations.

A ground for revocation under the basis that the cited design meets the s 15(2)(c) criteria does not take into account who the owner of the cited design is. That is, earlier applications and registrations by the same owner can result in the design being part of the prior art base and giving rise to a ground for revocation.
It does not matter whether an earlier application has lapsed or not lapsed. All that matters is whether the design has been published.
If at the time of certification, the design in the earlier application has not been published, a Certificate of Examination can be issued. However, if this design is subsequently published, it can be considered a valid citation (if re-examination of the later registered design is relevant). The fact that certification has occurred does not mean the ground for revocation no longer exists.
Where the earlier application includes more than one design, the ground for revocation is dependent upon the publication of the design that is relevant to the later registration that is being examined.
A lapsed unpublished application with a priority date earlier than the priority date of the registered design being examined is not part of the prior art base. However, if that application is restored (following an extension of time under s 137) and later published, the design(s) become part of the prior art base and citable against any design that has a later priority date.