humbled valiant wrote:
I just don't understand how the clips on a 66 block are connected to
each other. Are the rows connected?
Are the rows split? Are the columns connected? Are the columns split?

On all the ones I've ever seen or used:

None of the rows are ever connected to another row.

Sometimes all the columns in one row are connected to each other, and
nothing else.

Sometimes half of the columns in one row are connected to each other
(and nothing else), and the other half of the columns in that row are
connected to each other (and nothing else). This is often called a
"split" block. Applying a bridge connector across the middle two
columns in a split block turns it into an un-split block.

There are probably some obscure variants lurking in Bell System
documents from 1972, but I think pretty much everything you buy new
today will be one of the above two.

Matt Roberds