Board Thread:Support Requests - Getting Technical/@comment-24136187-20160526115359/@comment-24473195-20160526124325

Not sure why you added so many expressions. A simpler version would be:

The problem is that "{" has a special meaning in maths, and is not used at all by the expr parser function. So you need to use an alternative output when the variable "" is empty.

See:https://www.mediawiki.org/wiki/Help:Extension:ParserFunctions#.23expr