It is the law in Austaralia that all first-born boys MUST be called Bruce and first-born girls, Sheila. Many Australians register fake births just so that they can choose other names.
In the UK of course, a similar law applies to Charles and Diana.
The American version of this law allows variation according to ethnic origin, so African American boys may be called Errol, Hispanics, Juan, and so on.
those are two slightly different matters Xollob. Bruce used to be a moderately popular Christian name, though you don't hear it so much these days. But Sheila was never, as far as I know, a particularly common first name - it was a generic term for all women ('the sheilas') , which isn't quite the same thing.
ned I never heard an Australian say mucka in my life, I'm pretty sure that's pure Queen's English. 'Yole barstard' is the more usual term of endearment.