Being new to Rust I wasn't familiar with this acronym and found it hard to guess (the context of syntax trees biased me to reading it as a D-something Syntax Tree and trying to guess what the D was), hard to google (in retrospect googling "rust dst" does the job, but I thought it was an abstract structure thing, not Rust-specific), and hard to Github-search, because `dst` is commonly short for “destination” in code.
Alternatively `<abbr title="dynamically sized type">DST</abbr>` would be about as helpful.
