Add {clipboard} or {highlight} for the template variable for file name naming.

[okrightall]

First, check if there are any highlighted parts in the current tab of the browser. If there are, copy them to the clipboard, and finally use the contents of the clipboard as the name of the final saved file

[gildas-lormeau]

Copying the selected text of the page in the clipboard is outside the scope of SingleFile. However, I think I could implement the {highlight} variable.