Not all users were affected, but those who were saw their keyboards offering up "I.T" as a predictive text suggestion and an automatic autocorrection when typing "it." Some people also saw the word "is" autocorrect to "I.S."
The I.T. autocorrect problem has been around since iOS 11 first launched in September, but not every iPhone user experienced the issue. It appeared to be more limited in scope than a similar autocorrect bug that caused the letter "i" to autocorrect to "A[?]."
The "A[?]" bug was fixed in an iOS 11.1.1 update that was released to the public on November 9.
Reports on Twitter and reddit indicate that the iOS 11.2 update successfully fixes the I.T. autocorrect bug, so affected users should install it immediately.
iOS 11.2 also fixes several other bugs, including a major date-related bug causing crashing starting at 12:15 a.m. on December 2, and it introduces faster 7.5W wireless charging and Apple Pay Cash.