Currently, the core plugin Tempalte supports the variables title, date and time. For the date and time variables you can provide custom formatting appending the format after a colon :, like this {{date:YYYY-MM-DD}}.
I believe it would be amazing to be able to add modifiers also on the title variables, like:
{{title:U}}or{{title:L}}: to replace the title in uppercase or lowercase, equivalent totitle.toUpperCase()ortitle.toLowerCase(){{title:1}}or{{title:-2}}: to replace the title sliced form the beginning or the end of the string, equivalent totitle.slice(1)ortitle.slice(-2)
From my understanding, this cannot be currently done with the core plugin.