   [# document header #]
   # level 1 header #
   ## level 2 header ##
   ### level 3 header ###
   [internal reference text]
   [external reference text] {URL}
   <-- Table - caption text -->
   **bold text**
   <italic text>
   __underlined text__
   `literal text`
   "quoted text"
   ~~strike text~~
   ^(superscript text)
   _(subscript text)

   <```
   literal block
   ```>

   <"""
   block quote
   """>
