!Example
Here is an example of recognized characters.

This markup
{{{
-> <- <-> => <= <=> >> << -- --- ... 640x480 (c) (tm) (r)
"He thought 'It's a man's world'..."
1/4 1/2 3/4 +- 8^2 8^3 
}}}

Will render as:

%%(background-color:yellow;margin-left:2em;)
→ ← ↔ ⇒ ⇐ ⇔ » « – — 640×480 © ™ ® 
“He thought ‘It’s a man’s world’...” 
¼ ½ ¾ ± 8² 8³
%%

Reality check: (only when UserPreferences are turned on)

%%(background-color:yellow;margin-left:2em;)
-> <- <-> => <= <=> >> << -- --- 640x480 (c) (tm) (r) 
"He thought 'It's a man's world'..."
1/4 1/2 3/4 +- 8^2 8^3 
%%