A list of different types of a projective line over non-commutative rings
with unity of order up to thirty-one inclusive is given. Eight different types
of such a line are found. With a single exception, the basic characteristics of
the lines are identical to those of their commutative counterparts. The
exceptional projective line is that defined over the non-commutative ring of
order sixteen that features ten zero-divisors and it most pronouncedly differs
from its commutative sibling in the number of shared points by the
neighbourhoods of three pairwise distant points (three versus zero), that of
"Jacobson" points (zero versus five) and in the maximum number of mutually
distant points (five versus three).Comment: 2 pages, 1 tabl