Halfway down this page (it's a PDF doc):

http://www.cablesandconnectors.com/PIX/CC-040.pdf

the TNC and BNC connectors are advertised as "dual-crimp". What does this
mean? "Dual" as in center in crimp and outer shield ferrule crimp?

As opposed to what? Single-crimp? That would be connectors that use the
center, solid conductor as the center pin and then crimp the shield ferrule?
Or...?

Newly (did you guess?) into small coax connectors and trying to get the
terminology straight...

Thanks.