Today’s Unicode calligraphy is the good old ampersand. The name for the character comes from “and per se and”, but despite all sources agreeing on that fact, I couldn’t figure out what the longer phrase actually meant.
Looking at older sources, I think the phrase is supposed to be parsed ”& per se: and”. That is, ”& per se” means the character ”&” by itself, and the second “and” is a spelling-bee-style repetition to indicate that you have finished spelling the word “and”. So one might spell “wear and tear” out loud by saying:
W-E-A-R wear; & per se and; T-E-A-R tear
The same was apparently true for the words I, a, and O, so our national anthem would be spelled “O per se: O; C-A-N-A-D-A: Canada”.