> In Amber, there is a rule that allows you to use a : symbol where you intend to write only one statement, wherever you can write a block of code. This can be handy when you want to perform multiple conditions with a single statement each.

This feature, optional omission of delimiters in the special case of a single statement per branch, originated in early C and has since facilitated untold numbers of bugs, not least the spectacular Heartbleed bug (which has its own homepage, https://heartbleed.com).