Punctilio

punctilio \ˌpəŋk-ˈti-lē-ˌō\ noun: 1. a minute detail of conduct in a ceremony or in observance of a code, 
2. careful observance of forms (as in social conduct)

Etymology: Italian puntiglio point of honor, scruple, from Spanish puntillo, from diminutive of punto point, from Latin punctum

Merriam-Webster dates punctilio’s earliest written usage at 1596. Despite more than four hundred years of life on the lips of English speakers, the word doesn’t sound very English, at least to my ears.