Special:RunQuery forms do not work with #formlink. Links to Special:RunQuery forms need to be created as full URLs (protocol relative in MW 1.18+) with external wiki link syntax:
http://www.mediawiki.org/wiki/Help:Links#External_links_to_internal_pages
or with the fullurl magic word:
http://www.mediawiki.org/wiki/Help:Magic_words#URL_data
Both of those methods require the use of the plainlinks class to suppress the external link icon, like this:
<span class="plainlinks">[path/toindex.php/Special:RunQuery/form|template%5Bfield%5D=preload_data link text]</span>
or this:
<span class="plainlinks">[{{fullurl:Special:RunQuery/form|template%5Bfield%5D=preload_data}} link text]</span>
The Semantic Forms #formlink parser function seems to simplify the above two native MediaWiki constructs, and add some features specific to Semantic Forms:
http://www.mediawiki.org/wiki/Extension:Semantic_Forms/Linking_to_forms#Using_.23formlink
The documentation does not say anything about Special:RunQuery forms not being compatible with #formlink, so I assume that is either a bug or an oversight. I assume it was an oversight.
Version: unspecified
Severity: enhancement