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Isn't this spherical geometries? I may be wrong, but it seems like the Steiner $3$-design $S(3,q+1,q^n+1)$ for prime power $q$ and $n \geq 2$, where the blocks are the images of $\mathbb{F}_q\cup\{\infty\}$ under PGL$(2,q^n)$. I heard this was in Witt's 1938 paper. Don't quote me on this though. I don't speak German, so I haven't read the original paper. And if you found this in 1978, it's already before I was born!
@Gerhard I think it means each row and column is of uniform weight $k$. At least the conjecture on Zhan's list considers 0-1 matrices in which every row and column has exactly $k$ 1's.
@darij As Dima points out, that ranking contains questionable entries. And it misses obviously combinatorics journals that are by no means obscure (e.g., J. Graph Theory). I'm having very hard time believing journals were carefully categorized by active researchers working in each respective field.
