Re: Naming Standards clearly designed to confuse...
Yeah, either name consecutively (1, 2, 3, 4) or have a clear distinguisher (RPi 3+ has more on it but from the same series as the 3 - why do you need A or B AND a plus?).
Otherwise it's gets too tricky.
Basically:
Zero = very tiny one.
Pi 1 = single-core 700MHz, 256Mb/512Mb, composite video (later ones had HDMI - grr!)
Pi 2 = quad-core 900MHz, 1Gb, HDMI
Pi 3 = quad-core 1.2+GHz, 1Gb, HDMI
The + models have more USB / Gigabit Ethernet / faster speeds.
But they really mess it up by randomly changing things between models, including three models of zero, the compute modules, putting pins only on certain models (e.g. the PoE pins?), and changing the form factor and even layout between each one.
It would be much easier to standardise the modules, and just not solder the extra components onto the smaller models, just like every other manufacturer does.
Basically, stick with the highest numbers, largest-lettered model available (RPi 3B+ at the moment) unless you have a particular pressing need to optimise power / space.