Answer
Each selected line becomes a Markdown quote, including blank lines within the passage. Hashchats keeps your existing draft and attachments, appends the quote after a blank line, and places the cursor on a blank line below it. Repeat to collect multiple passages before writing your question. Existing trailing blank lines are preserved. If the combined text exceeds the current composer's limit, an error leaves the draft unchanged. Add what you want, such as an explanation or rewrite, check Text is selected, and send. Selecting text alone does not send a request.