David Peters wrote:
I want to hang something up in my kitchen and I need to drill some
holes into the ceramic (pottery) tiles.

I'd like to have a symettrical look and this means drilling one of
the holes right in between two tiles.

I'll use the correct spear-shaped drill bit, apply little pressure
and make sure the bit is kept cool during drilling.

QUESTION: Is drilling between two tiles (they look about 20 years
old) so likely to chip, crack or otherwise damage them that I'd be
much better off drilling somewhere else on the tile?

It's quite possible to drill tiles that are fixed with an ordinary
masonry drill in a hammer drill (pref with variable speed), but it does
depend how they are fixed, ie, how much adhesive is behind the spot you
are drilling. Lots of adhesive and no voids then it's OK.

MBQ