* doc/lispref/frames.texi (Child Frames): Fix wording (Bug#28819).
@item
The semantics of maximizing and iconifying child frames is highly
window-system dependent. As a rule, applications should never invoke
-these operations for on frames. By default, invoking
+these operations on child frames. By default, invoking
@code{iconify-frame} on a child frame will try to iconify the top-level
frame corresponding to that child frame instead. To obtain a different
behavior, users may customize the option @code{iconify-child-frame}