ASCII 100 — d

The lowercase letter d (ASCII code 100) is the small form of the fourth letter in the Latin alphabet. Lowercase letters emerged from medieval scribal handwriting traditions where faster cursive writing produced smaller, rounder letterforms that eventually became standardized during the Renaissance era. In hexadecimal, 'd' represents decimal 13. The letter is commonly used as an abbreviation for 'day', 'date', or 'delete' in programming shorthand.

The 26 lowercase Latin letters occupy ASCII codes 97 through 122, positioned exactly 32 code points after their uppercase equivalents. This systematic offset allows case conversion by toggling bit 5 in the binary representation — an elegant design choice from 1963 that still enables efficient case-insensitive string operations in modern software. Lowercase is the default case for most programming identifiers, Unix commands, file names, and body text, making these characters among the most frequently encoded in the entire ASCII set.

In the ASCII encoding table, Lowercase Letter d is assigned code point 100 in decimal (0x64 hexadecimal, 144 octal, 01100100 binary). The 7-bit ASCII standard, first published in 1963 by the American Standards Association, defines exactly 128 characters that remain the foundation of text encoding systems worldwide. UTF-8, the dominant encoding on the modern web, is fully backward compatible with ASCII — every ASCII character is encoded as the identical single byte in UTF-8, guaranteeing that Lowercase Letter d works reliably across all operating systems, programming languages, and internet protocols.