I was thinking about this:
in the old old days, the service numbers were just printed on the
plates with no annotation or whatsoever. if i not wrong..
then when sbs became under delgro, they have a unified plate which
has the sbs logo at the left and the services listed in a
grid.
for tibs back then, it's the gray tibs logo n the services listed
in a grid.
after a massive switchover where bbt handed to tibs, they
customised the plates such that they display the routes..
well i cant remember a lot ogf things so i hope people here can
fill in the missing pieces 
it's
quite exciting to see the bus stand plates as a accompaniment to
buses evolve over the years
