In Dungeons & Dragons, the Sending spell can convey exactly 25 words. In reality, linguists are unable to precisely pin down what a word is. Sending is one of only a few long-distance magical communication methods in the worlds of D&D, and this makes it an important tool in the hands of those who run large organizations, kingdoms, or empires.

This implies that mystical linguists in D&D worlds are out there pushing the technological boundaries of what constitutes a "word", experimenting with different hyphenation techniques, and assembling new compound languages like the fabled "Hypergerman", which are particularly amenable to compounding. All to improve the efficiency of
Sending, and eke out a little more information from each scarce spell slot. How much additional information can you add if you start experimenting with tones?

I'm just imagining the æther-messengers of the Imperial Bureaucratic Service constructing Sendings with all the comprehensibility of a dialup modem sound, and blasting out whole paragraphs of information to someone on the other end who has
Keen Mind and has to spend an hour with a diabolical grammar and particle reference translating this data-pulse back into the trade tongue.

@tilde @Flyingmana It depends on the CPU architecture used to cast the spell.

If it’s an old architecture, word size might be 8-bit or 16-bit. However, newer architectures use 32-bit or 64-bit words. In terms of programming, the spell might use WORD (16 bits/2 bytes), DWORD (32 bits/4 bytes) or QWORD (64 bits/8 bytes) structures.

x86 architectures commonly use 16 bits as the base word size, while IBM S/360 uses 32 bits.

Assuming 16-bit words, the caster can send 50 bytes of data.