quincunx
ˈkwɪnkʌŋks/Submit
noun
1.
an arrangement of five objects with four at the corners of a square or rectangle and the fifth at its centre, used for the five on a dice or playing card, and in planting trees.
2.
ASTROLOGY
an aspect of 150°, equivalent to five zodiacal signs.
Becouse its a reminder.Well if it is truly a well known prison tattoo but you are being genuine about it being a personal reminder for you only, then why put it in such a visible place?
probably a good idea.Because you'd be reminding everyone else at the same time? It ends up looking more like you want people to know you've been to mental hospitals, rather than a reminder to yourself not to go back, and people will assume it was prison (and I'm guessing the only people who would know are ex-convicts)...
Why not have it somewhere more discreet?