NSW BDM has 50 year closure, but I think Vic BDM has a different process, I think, (not sure) that there's a lengthy number of years for the restriction, but also that both bride and groom need to be deceased.
We married in 1974, in NSW. My older brother married in NSW too, and so too all my siblings, all my first cousins, my parents, my grandparents (and their respective siblings) my greats etc... I know that I could spend some pennies and obtain the m.c. for my living relatives who married more than 50 years ago. But on the other hand, I actually attended the weddings for my cousins, sometimes in the official party. As they are living relatives if I want confirmation of their details I would simply ask them for those details. If they are not family history buffs, then I would gently mention of course that their m.c. is publically available, anyone can purchase without id etc... and if I were to purchase I would give them a copy of that record/document.
There is an increasing trend to tighten the already tight privacy rules/practices etc, so perhaps this is a sensible time to share a pdf file about Australia's privacy (Office of Australian Information Commission)
https://www.oaic.gov.au/resources/agencies-and-organisations/guides/what-is-personal-information.pdfhttps://www.oaic.gov.au/media-and-speeches/news/the-oaic-welcomes-the-appointment-of-angelene-falk-as-australian-information-commissioner-and-privacy-commissionerWhat information is actually on a NSW marriage Certificate ? from NSW BDM website:
https://www.bdm.nsw.gov.au/Pages/family-history/registry-records.aspxBridegroom's full name, occupation, place of residence, conjugal status, place and date of birth, age, father's name and mother's maiden name.
Bride's full name, occupation, place of residence, conjugal status, place and date of birth, age, father's name and mother's maiden name. Celebrant's name and witnesses.So there's lots of personal/sensitive information there.
JM
ADD, I have checked my copy of the NSW BDM registration of my marriage (needed to obtain certified copy for passport purposes) and the depth of detail gives not just my father's occupation, but by virtue of his occupation, it gives his employer details too...
Similarly for my husband, because of his occupation as described on the 1974 registration, it is obvious to any NSW family history buff who he worked for at that time.
privacy ! ummmm....