The term "143" is often used as a numerical shorthand for the phrase "I love you." This comes from the number of letters in each word, where "I" has 1 letter, "love" has 4 letters, and "you" has 3 letters. It is commonly used in texting and online communication to express affection in a concise manner.
The expression "143" originated from the early days of texting and digital communication, where brevity was essential. It reflects a creative way to convey deep emotions using limited characters.