A monogram is a gram with one line. That line can either be a broken line (0) or a full line (1).

The monogram is the building block of grams, and it represents the duality of things.

Here's some additional info:

Binary name: 0 - 1
Name used: yin - yang

Meaning: n/a

Mapping examples:

yin - yang
broken line - full line
persistence - change
background - foreground
black - white
form - idea
feminine - masculine
static - dynamic
focused - unfocused
microscopic - macroscopic
down - up
nothing - everything
past - future

Everything is relative; everything is defined by its opposite.

That means there are plenty of things we can map to yin-yang to suit our needs.