I discovered that the pipeline character ("|") renders as a colon (":").

Is this intentional or just a copy/paste bug in the font?

It probably looks like a colon, but I bet it's supposed to represent a broken vertical bar. So it's not technically a bug, but for readability sake it might be a feature request a for font improvement.

Nah, it's not a broken vertical bar. It's a colon. A broken vertical bar would, almost guaranteed, be rendered like this:

_X
_X

_X
_X

But this renders exactly like a colon:

_X

_X

I suppose it's possible zep didn't realize that a broken vertical bar shouldn't look like a colon, in which case the bug is that it does and it shouldn't. :)

But really, it's a pipeline character, the same one we use for 'or' in C++, and these days the standard visual for it is a full, unbroken vertical bar:

X_
_X
X_
_X
_X

(As I recall, unicode added a broken version so one could use either, as desired.)

If it weren't for the fact that it does need to be broken row-to-row, I'd even suggest going into the descender space, but that's not feasible with a 4x6 font.

This matters, btw, if you're making character-based text boxes, e.g. oldschool RPG/adventure style. The colon-like character doesn't cut it for a vertical line in the frame.

(BTW, I personally would wish for the ability to override the built-in font, much like you could on a C64 or the like.)

Just noticed someone screenshot the character set, so I thought I'd use it to highlight the problem: