I think Aleph means coins struck
before the mid-1st century BC, the starting point chosen by
RPC being the death of
Caesar in 44. So much of the "
Imperatorial period" is actually covered. But in the absence of an Imperial (or
Imperatorial)
bust or name on the coin, it can be hard to pin it down to a narrower date of issue than, say, "1st cent. BC". I have a number of coins that I reckon were struck mid- to late-century, but no way of proving it.
It would be
good if someone worked on those coins at the
ANS!