Template:PagesStartingWith

https://wiki.qemu.org/index.php?title=Special:AllPages&from={{{1}}}&to={{{1}}}zzzzz&namespace=0

Documentation

Used to link to pages starting with a given prefix.

Example

[{{PagesStartingWith|Testing/}} All testing pages]

⇒ All testing pages

However there is already a built-in way of transcluding a list of all sub-pages into your page:

{{Special:PrefixIndex/Testing/}}

Would give you:

It is suggested to use this template only when the list would be too long, and the "parent" page is already listing an interesting subset of pages. For an example, see Documentation or Features.