Open https://en.wikipedia.org/wiki/User:Neil_P._Quinn-WMF/T106902?veaction=edit, which contains the wikitext:
```
{{stnlink|Gloucester}}
One <nowiki><pre></nowiki> block
Second <nowiki><pre></nowiki> block
```
Try to delete the first `<pre>` block. If you simply select from before the "O" in "One" to after the "k" in "block" (5-20 in the linear model) and press delete, you'll be able to delete the contents of the block, and another delete will get rid of the containing `<pre>` block.
//However//, if you select from after the "r" in the "Gloucester" template to before the "S" in "Second" (3-22 in the linear model) and press delete, the first `<pre>` block won't be deleted. Instead the contents of the //second// `<pre>` block will turn into plain text and jump up to the first line, beside the "Gloucester" template.