I don’t like reStructuredText’s backslash behaviour, because it means two completely different things. Or arguably three. Normally it means to interpret the next character literally, but if it’s followed by whitespace (typically space or newline) it instead removes that next character. Except… not entirely in the case of newline, because it’s character-level markup, and at the end of a block it just does nothing. In

  a\
   b
you might expect to get “a b” or an error, but actually you get a single-item definition list with term “a” and definition “b”, just the same as if you had omitted the backslash.

A far more logical meaning of a trailing backslash is to escape the newline, meaning, in HTML terms, insert <br>. That’s what I chose in my LML, and I later learned CommonMark chose that too.

> meaning of a trailing backslash is to escape the newline

That's what it does in this example. Don't have to use other cases, and don't believe I did.

In hindsight “escape” was a poor choice of word, but I did explain it and you omitted that from your quote: “meaning, in HTML terms, insert <br>”. And that’s not what reStructuredText does. Rather, at the end of a line, backslash acts like a line continuation character (… that only works in certain circumstances), a behaviour commonly found in programming languages inside at least string literals, but such languages aren’t using backslash as “escape the next character”, but rather they have a fixed set of escape sequences like \n or \uXXXX.