Author: vinaur
Description:
When creating tag extensions, attribute names with underscore as the initial character (e.g. _attr, _file, etc.) are not recognized as valid attributes. This is a valid attribute name according to W3C XML standard (http://www.w3.org/TR/REC-xml/#NT-NameStartChar), which, if I understand correctly, mediawiki tries to comply with.
I don't see a reason why these attributes should not be allowed.
Version: 1.17.x
Severity: minor