I before E, except after C

Etymology
Formed because of the rhyme between the names of the letters E and C, and. The "rule" was invented in the 19th century.

Proverb

 * 1)  In English words that contain the letters I and E together, the I tends to come before the E (ie), except in cases when the two are preceded by the letter C, in which case the E comes before the I (cei).