-RECURSIVE determines what to do with a non-empty directory. If RECURSIVE is:
-nil, do not delete.
-`always', delete recursively without asking.
-`top', ask for each directory at top level.
-Anything else, ask for each sub-directory."
+RECURSIVE determines what to do with a non-empty directory. The effect of
+its possible values is:
+
+ nil -- do not delete.
+ `always' -- delete recursively without asking.
+ `top' -- ask for each directory at top level.
+ Anything else -- ask for each sub-directory.
+
+TRASH non-nil means to trash the file instead of deleting, provided
+`delete-by-moving-to-trash' (which see) is non-nil."