The 404 page selection Template Manager > Template settings only shows ~ 100 templates as expected, however, when searching it only searches the 100 initially listed. That is, you cannot select a template beyond the first 100 shown even with search.
ExpressionEngine implements Markdown Extra and BBCode. Please see the Markdown Extra docs and the BBCode Wikipedia article for a full reference.
**bold**, __bold__, *italics*, _italics_, ~strike/del~, `code()`
bold, italics, strike/del, code()
Link: [link title](https://example.com)
Image: 
[blockquote]...[/blockquote], [quote]...[/quote], and Markdown style:
> Some quoted text. > > This is all one quote.
[code]...[/code], and you can also specify the language for syntax highlighting, [code=php]...[/code]
GitHub flavored Markdown code fences are also supported:
```
public function decoderRing($str)
{
return str_rot13($str);
}
```