When a string is created using @code{buffer-substring} or
@code{buffer-string}, any duplicable extents in the region corresponding
to the string will be copied into the string (@pxref{Buffer
-Contents}). When the string in inserted into a buffer using
+Contents}). When the string is inserted into a buffer using
@code{insert}, @code{insert-before-markers}, @code{insert-buffer} or
@code{insert-buffer-substring}, the extents in the string will be copied
back into the buffer (@pxref{Insertion}). The extents in a string can,