Scratch on swingarm

I've got a little scratch, about 1/2 cm long, in the shape of a crescent on my swing arm. No idea how it got there - I'd have expected a stone to give a straight scratch, or it's possible (probable) I did it when I was struggling with my paddock stand (tho I thought I was being very careful!). That aside, what should I use to paint over it? Would something like black hammerite do, or is there something special to do these sorts of touchups?

I'm pretty annoyed with myself for having done it, but I guess it's not as annoying as dropping it, which thankfully I've not done yet!

many thank

ive got the same crescent shaped scratches on the swingarm, around where the bobbin screws in. It was done by the previous owner (i didnt have a swingarm until recently). Being a silver swingarm, its not too noticeable, only when you get up close. Thats really the only thing on the whole bike which is marked.