I was learning about cutting/scratching. This is a pagan practice of cutting oneself in mourning, and is forbidden in the Torah.
No measure is given for what counts as a שריטה/גדידה, even though other details are given, and measure is given for other halachot in this siman, such as קרחה.
Rambam always gives a measure, and where he doesn't (like with this), you can be sure that there is no minimum measure. However, there are exceptions to every rule so I thought I'd ask if anyone is aware of a minimum measure?