Taken from English Wikipedia

[[Template:Convert]] is actually a good example of where TemplateData falls over and hits the ground. The meaning of the numbered parameters changes depending on how many of them there are and whether the entry is text or a number. For example, each of the following are valid:
{{convert|3.21|kg|lb}}
3.21 kilograms (7.1 lb)
{{convert|3.21|mi|3}}
3.21 miles (5.166 km)
{{convert|60|to|170|kg|lb}}
60 to 170 kilograms (130 to 370 lb)
{{convert|60|+/-|10|kg|lb}}
60 ± 10 kilograms (130 ± 22 lb)
{{convert|6|ft|5|in|m}}
6 feet 5 inches (1.96 m)
In those examples, parameter 3 is variously 1) The output unit, 2) The number of significant figures, 3) The upper limit of a range, 4) The measurement uncertainty, 5) The number of inches in foot-inches measurement. Now write a TemplateData description for parameter 3 (or 2 or 4 or 5)? Convert is used on 500,000+ pages, so it is not like it can simply be redesigned at this point. That said, if someone can see the values of each parameter in the transclusion window then it would still be pretty easy to figure out which one they need to edit. I would suggest that the transclusion editor needs a way to preview the parameter contents (even if just a snippet) without having to click on each parameter. Dragons flight (talk) 17:57, 5 July 2013 (UTC)

Version: unspecified
Severity: enhancement