\begin{definition}[Definition:QEF]
The initials of '''Quod Erat Faciendum''', which is {{WP|Latin|Latin}} for '''which was to be done'''.
These initials were traditionally added to the end of a geometric construction.
This is practically never seen nowadays outside translations of {{ElementsLink}}.
If there is a need for such an indication, the Halmos symbol $\blacksquare$ would be used instead.
{{ProofWiki}} does not bother to distinguish between use of '''QEF''' and the better-known '''QED''', and recommends the use of the {{TL|qed}} template exclusively instead.
\end{definition}