Single asterisks: *italic text*
Single underscores: _italic text_
Double asterisks: **bold text**
Double underscores: __bold text__
Combined: **bold with *nested italic***
Mixed markers: *italic with **bold** inside*
Adjacent: *first* and *second* emphasis
Intraword: un*frigging*believable and un**frigging**believable
This is _ not emphasized _