Enter a header (on its own or attached to something) to get info and formatting; hover over parts of the info/header to highlight related text; the character set indicator gets underlined in dashed blue and the syntax character exclusions in dotted orange; everything else is hopefully evident if you have a basic understanding of the format.
(You won't need to change these settings for basic headers such as the examples given in the format description.)
Default character set: | (ID enclosed in slashes, or literal character list)
Syntax start:
Text with header:
Trim leading whitespace
Syntax characters:
Character set: