[qxyxntvs] List of escapes

Markdown requires backslash-escaping the following 17 characters: \ ` * _ { } [ ] ( ) # + - . ! < & (The last two are not listed in the linked documentation, but are needed when writing about HTML but not using code spans or blocks.)

LaTeX requires being careful about the following 10: $ # % _ { } ^ ~ \ &

HTML requires using an entity to denote the following 2: < &

C strings require a backslash escape for the following 2: \ "

This blog recently switched to Markdown-based composition.  Things may go wrong if I forget which characters need to be escaped when.