adjective
punctilious
punk-TIL-ee-us/pʌŋkˈtɪliəs/
Extremely attentive to details of rules or proper behavior.
The punctilious man measures the fork's position in the formal place setting.

Etymology
The probable Italian source centers on a “fine point.” Applied to behavior, attention to such points means exact observance of even small details of rules, manners, or custom.
In context
I didn't want to make a lot of errors in spelling. These Italians are so very punctilious.
More examples
- Our host is punctilious about making proper introductions.
- Even during heated debates, he remains punctilious about addressing colleagues respectfully.
- The committee is punctilious in observing its voting procedures.
Forms
punctilious · more punctilious · most punctilious
punctiliously adverb — With exact attention to rules or etiquette.
punctiliousness noun — Strict attention to rules or proper behavior.
Similar words
- meticulous
- Emphasizes careful attention to any details, not specifically proper conduct.
- scrupulous
- Often emphasizes moral honesty rather than exact observance of etiquette.