CONSTELLATIONS BY SEASON
the northern evening sky through the year: 28 constellations per the Yale Bright Star Catalogue, latitude 40° N, evenings near 9 pm
METEOR SHOWERS
the twelve principal showers of the year · periods, peaks and ZHR per the IMO calendar
MARS
size, distances and time — computed from rotation, orbit and mass
SPRING AND NEAP TIDES
the Earth–moon–sun geometry that makes the tides swing — after NOAA
BLOOD PRESSURE CATEGORIES
the six AHA categories · 2025 guideline · the higher of the two readings decides
CPR AND CHOKING
the 2025 American Heart Association algorithms, step by step — bystander, trained rescuer, and choking at three ages
DRESS CODES
six lines that turn up on an invitation, and what each one actually asks for — after Debrett’s
THREE HAND STITCHES
backstitch · running stitch · whipstitch — what shows on the face and what the thread does underneath
THE CHILD IMMUNIZATION SCHEDULE
Table 1 of the CDC schedule, by age: all twenty rows from birth to 18 years, United States, 2025
LAUNDRY CARE SYMBOLS
the 28 symbols of the everyday clothing tag per ISO 3758:2023: five treatments in a fixed order, sharing one set of modifiers
MAGNESIUM COMPOUNDS
the share of magnesium in the salt, computed from the formula · and what human trials measured
NAIL SHAPES
eight shapes at one scale · what tells them apart in millimetres