This file contains 12 links of the form "xY", with "x" fixed and "Y" possibly varying.
Each link points to a webpage that in turn points to files of the form "?xY*"
("?" is a single-character wildcard and "*" is a multiple-character wildcard.)
xa
xc
xd
xe
xf
xg
xn
xo
xp
xv
xx
xy