The baby names you're about to hear everywhere thanks to the '100-year rule'.

How long does it take a name to go from fresh to hopelessly dated to fresh again? Apparently, about a century. It's known as the Hundred Year Rule, and it means that baby names that were popular in 1923 should sound appealing to parents right about now (think Leo, Florence, Hazel, Harvey).

American naming site Nameberry has come up with a list of 20 names from the US top 100 from 1923 that haven't yet been revived in the States but could be.

Some of them are right on the money. For girls, Nameberry likes Agnes (as in the saint), Betty (the name chosen by Blake Lively and Ryan Reynolds for their daughter in 2019), Marjorie (a medieval form of Margaret), Minnie (a super-cute nickname) and Viola (as in Oscar-winning actress Viola Davis). Less likely to work in Australia: Pauline, despite Nameberry describing it as being "sleek" and "on trend".

For boys, Nameberry's choices include Chester (the name of Tom Hanks and Rita Wilson's son), Clarence (from the royal title Duke of Clarence), Ernest (sure to get a boost now that Princess Eugenie has given it to her baby), Floyd (cool musical connotations thanks to Pink Floyd), Milton (another surname-style name) and Ralph (already popular in the UK). Less likely to work in Australia: Virgil, because you just know kids at school will turn the "l" into an "n".

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So what about names that were popular in Australia in 1923 that haven't yet been revived? A lot of them seem just too... well, Australian. It's hard to imagine anyone wanting to call their babies Sheila and Bruce, Norman and Norma, Neville and Noel, Barry and Trevor, or Beryl and Muriel (as in "You're terrible, Muriel!"). Maybe we need a hundred years and 15,000 kilometres for names to feel truly fresh?

But looking at the list of popular names and squinting a bit, there are a few possibilities. Try out these 10 vintage selections and see how you like them.

Mavis

The name of a bird also known as the song thrush, Mavis is a great nature name. It's already starting to make a comeback in the US.

Myrtle

It wasn't that long ago that plant names like Hazel and Olive sounded terribly old-fashioned. Surely Myrtle, as in the flowering greenery, has to be next in line for revival?

Nellie

A pet form of names like Helen and Eleanor, Nellie has a sweet sound to it and fits in nicely with Ellie, Ella, etc.

Peggy

While Maggie has been brought back in a big way, Australians haven't taken to this pet form of Margaret in the same way – yet, anyway.

Veronica

Veronica Mars, Veronica from Archie Comics, the Veronicas... it's a surprise this long, lovely name isn't more popular.  

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Herbert

Comes with two built-in short forms, Herbie and Bertie, which would blend in perfectly with names like Archie, Billy, Charlie, etc.

Reginald

Reg, Reggie, Reginald… take your pick. The name was well used in the US until quite recently and has a younger image over there. 

Rex

Maybe it's better known as a dog's name, but who doesn't love dogs? In the US, Rex, which is Latin for "king", is starting to be used for girls and boys.

Roy

A Scottish name meaning "red", Roy has mostly been heard recently as a surname on Succession. Short and strong.

Wilfred

It might give some people flashbacks to studying Wilfred Owen poems in high school English, but Wilfred is getting popular again in the UK and could take off in Australia.

Feature Image: Getty.