Board Thread:General Discussion/@comment-25952539-20160429084124/@comment-24473195-20160429092601

I don't think it would help much. Some people actually create multi-part templates with unclosed tags for several uses. A template called Template:Scrollbox seemed to use that.

The fact of the matter is that there is no such thing as invalid wikitext, and the developers who created wikitext seemed quite desperate to make sure that this remains true. At worst only extension tags (e.g. <source)  display some errors when they are misused, although even that can be violated by using the {{#tag function.

Even if such a page were to be created, it would be buried under many pages and few would find it. The best way to develop help is to only put it in areas of the software that those errors can be made.