THE ASCII TABLE
all 128 positions: the column is the three high bits, the row is the four low ones
THE BASE32 ENCODING
forty bits to a quantum: five bytes, eight characters and five padding cases
THE BASE64 ENCODING
three bytes become four characters: the alphabet, the tail, and what the "=" at the end is for
HTTP METHODS · 2026
ten methods per RFC 9110, 5789 and 10008: which are safe, which are idempotent, which can be retried
SPECIAL-PURPOSE IPv4 BLOCKS
14 blocks that belong to no host on the internet — 13.8 % of the address space, of which exactly one eighth is multicast and reserved
KANBAN
the board, the limit on work in progress, and the four metrics that measure flow
QUOTING IN THE SHELL
29 characters named by the standard, 4 ways to take the meaning off them — and the 3 characters where double quotes stop
INSERTION SORT
the way cards are ordered in the hand · the trace of one real run
QUICKSORT
splitting around a pivot · the trace of one real run
TWO-CAMERA SPEAKER SETUP
the lighting triangle and where each of the 2 cameras stands · the floor plan from above
THREE-CAMERA SPEAKER SETUP
the lighting triangle and where each of the 3 cameras stands · the floor plan from above
SUBNET MASKS
from /0 to /32: the mask, how many addresses a block holds, and how many of them go to hosts