Don't use @deffn Subroutine.

doc/lispref/files.texi

@@ -1550,13 +1550,13 @@ complete and relative specifications can be combined, as in
 symbolic mode bits specifications.
 @end defun
 
-@deffn Subroutine file-modes-symbolic-to-number modes &optional base-modes
+@defun file-modes-symbolic-to-number modes &optional base-modes
 This subroutine converts a symbolic specification of file mode bits in
 @var{modes} into the equivalent numeric value.  If the symbolic
 specification is based on an existing file, that file's mode bits are
 taken from the optional argument @var{base-modes}; if that argument is
 omitted or nil, it defaults to zero, i.e.@: no access rights at all.
-@end deffn
+@end defun
 
 @defun set-file-times filename &optional time
 This function sets the access and modification times of @var{filename}

doc/lispref/markers.texi

@@ -575,13 +575,13 @@ any subsequent command that moves point and is not shift-translated
 action that would normally deactivate the mark.
 @end defopt
 
-@deffn Subroutine use-region-p
+@defun use-region-p
 This function returns @code{t} if Transient Mark mode is enabled, the
 mark is active, and there's a valid region in the buffer.  Commands
 that operate on the region (instead of on text near point) when
 there's an active mark should use this subroutine to test whether to
 do that.
-@end deffn
+@end defun
 
 @defopt mark-even-if-inactive
 If this is non-@code{nil}, Lisp programs and the Emacs user can use the