I'm not convinced that, in the 14 segment font, we should just give up and accept that lower case "a" and "m" should just be the same as their upper case counterparts:

We can represent a "double storey" a like this:

   ___
      |
   ___|
  |   |
  |___| 

It's also unclear why we couldn't have a 14 seg lower case m like this:

   _ _
  | | |
  | | |

Maybe for each character, have a link to a documented rationale.

EDIT: Oh, look at the example font sheet featured in Wikipedia's Fourteen-segment-display page: it has these letters exactly as I say:

https://en.wikipedia.org/wiki/Fourteen-segment_display#/medi...