The anchor template special:anchor allows you to add HTML anchor tags (<a name=''>) into the wiki page. This can be useful to have named (and stable) link targets.
The template has one anonymous parameter: the name of the anchor.
Format: the anchor name has to be a valid wiki pagename, i.e. no spaces, only chars and numbers. The anchor name must not use names which are generated automatically (e.g. 'diag12', 'toc3', 'r4', '2'.)
{{special:anchor | coolSection }}
results in
(well there's nothing to see here, but if you look at the HTML code, you see the anchor being inserted :o)
Once an anchor is defined you can link to it, like you link to other HTML anchors in the page: