LMK

When you want someone to reply to a message, email, online post, etc., send them "LMK," which stands for "let me know." You can also use it to mean "letting me know," as in "Thx 4 lmk."

LMK works as a single statement or part of a sentence. For example, if you need to know a headcount for reservations, you might text your friend, "LMK!" if you've already asked them four times previously. Or, you might post on Twitter, "Does anyone have good show recommendations to binge-watch? LMK!"

LMK is one of many options for prompting a reply from the recipient. Other common choices include LMKWYT, WB, lemeno, and TMB.