# IBS vs iff

> English confusable word pair

## The two words

### IBS
*adjective · IPA /aɪ.biːˈɛs/ · frequency rank #32,851*
Initialism of identical by state.

### iff
*conjunction · IPA /ɪf ən(d)ˈəʊn.li ɪf/ · frequency rank #45,443*
Abbreviation of if and only if.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/vs/ibs-vs-iff