Or they write "See [[xxx]]" or "''See also:'' [[xxx]]", etc. Providing appropriate "tags" like "<seealso>" can help for better uniformity.
But you will have to end that with an </seealso> tag, too, and that IS already far too difficult for most of the people I consider to be very interesting authors.
XML is *not* meant to be edited by tools, but not directly by humans unless when absolutely needed.
Please leave the section markup as simple as possible. Some naming rules (Always use ==Further Information==; ===See also===; ===Literature===, no matter how ugly it looks right now in our skins!) will fully do. Everyone can learn that easily, it's intuitive (<seealso></seealso> is not!), it's uniform and it can be easily handled automatically to produce true XML when needed.
Uli