I looked on Wikidpedia:
“To come” is a printing and journalism reference, commonly abbreviated to “TK”. The abbreviation is used to mark where additional material will be added to a manuscript before publication.[1][2] It is used without periods.[3]
The use of the abbreviation is to prevent the phrase “to come” from being mistaken as a deliberate part of the text.
Since very few English words feature the letter combination TK, it is more easily searchable than TC. The abbreviation TK, as well as the repeated TKTK, is a “unique and visually arresting” string that is both easily seen in running text.[1] Therefore, TK is conducive to effective copyediting and proofing.
^^^^^^
I learn something every day because of FR. Yay!😀
TK = Tiny Killerbots! That’s a bit scary but it seems to fit right into the malodorous plans these devious corrupt sociopaths have.
It didn’t work this time.