The stations between Malvern and South Yarra are colloquially known as the MATHS stations.
The first four of them (that would be MATH) also match architecturally. I’m assuming they were all built around 1915 when the line was quadruplicated.
I can’t think of any other station group names of this type around the place, apart from more official terms such as the City Loop.
(This is one of those times when I feel like briefly writing about something which I suspect is widely known, but doesn’t appear to be definitively online anywhere. And I’m going to link back to it in a later post.)