AS NZS 1158.6:2015 Lighting for roads and public spaces
2.8.2.1 General
Top-entry luminaires shall be provided with a device to assist standardization of luminaire attachment. It enhances correct alignment and eases installation and removal of the luminaire.
2.8.2.2 Primary retention system
A spigot of the dimensions shown in Figure 2.1 shall be incorporated into the luminaire for attachment to the relevant lighting pole or outreach bracket end.
2.8.2.3 Secondary retention system
A secondary means of retention, separate from the primary retention system, shall be provided to prevent the luminaire falling from the pole or outreach bracket in the event that the primary retention system fails. This secondary retention system shall be capable of supporting the applicable static load, but it is not required to withstand the design loads applicable to the primary system. Figure 2.1 provides the interchangeability instructions.
2.8.2.4 Pole entry
The spigot specified in Figure 2.1 is dimensionally compatible with the pole entry detailed in Figure D1 in Appendix D, and the two combined provide a number of advantages,including ease of installation and secondary retention of the luminaire.
2.8.2.5 Coupling strength
All structural details of the spigot and pole end for any given luminaire and wind category shall be designed using appropriate engineering principles and taking account of the following:
(a) The existence of manual handling regulations that might impact upon the installation and maintenance of the luminaires.
(b) The loadings applied by the intended luminaire to the pole.
(c) The loadings applied by the intended pole to the luminaire.
(d) Limitations on the application of the particular luminaire, as stated in the  manufacturer’s installation sheet.
NOTES:
1 This detailed design process would typically be arranged by the luminaire supplier.
2 It is anticipated that the spigot detailed in Figure 2.1, used in conjunction with the pole entry detailed in Figure D1, can support masses in the range indicated for side-entry luminaires in Table 2.2 in environments subject to various wind categories as defined in AS/NZS 1170.2.
3 The maximum applicable mass and wind category will depend on various factors, including the sail area of the luminaire, the exact material used for the spigot, the material and wall thickness of the pole entry and the presence or absence of the supplementary row of screws shown in Figure D1.