Punctilious

/pʌŋkˈtɪl.i.əs/ adjective hard

Showing extreme, careful attention to precise detail and correct behavior.

The punctilious librarian re-shelved every book to the exact inch, following the catalog system to the letter.

Memory Trick

Contains 'punct,' as in 'punctual' or 'point' - a punctilious person hits every single point precisely, never missing a detail.