Oftentimes in math the **manner** in which a solution to a problem is announced becomes a significant chapter/part of the lore associated with the problem, almost being remembered more than the manner in which the problem was solved.  I think that most mathematicians as a whole, even upon solving major open problems, are an extremely humble lot. But as an outsider I appreciate the understated manner in which some results are dropped.

The very recent example that inspired this question:

- In updating his homepage to a single, austere line, Tim Browning [announced](https://pub.ist.ac.at/~tbrownin/) a solution to $a^3+b^3+c^3=33$ with $(a,b,c)\in\mathbb{Z}^3$ as $$(a,b,c)=(8866128975287528,-8778405442862239,-2736111468807040).$$  In the update, Dr. Browning did not even indicate that this is/was a semi-famous open problem, nor did he indicate that the cubes actually sum to $33$, apparently leaving it as an exercise for the reader.

Other examples that come to mind include:

- In 1976 after Appel and Hakken had proved the Four Color Theorem, Appel [etched](http://historyofmathematics.org/wp-content/uploads/2013/09/2004-Walters.pdf) on the University of Illinois' math department blackboard "Modulo careful checking, it appears that four colors suffice."  The statement "Four Colors Suffice" was used as the stamp for the University of Illinois at least around 1976.
- In 1697 Newton famously offered an "anonymous solution" to the Royal Society to the [Brachistochrone problem](http://www-history.mcs.st-and.ac.uk/HistTopics/Brachistochrone.html) that took him a mere evening/sleepless night to resolve.  I think the story is noteworthy also because Johanne Bernoulli is said "recognized the lion by his claw."
- As close to a literal "mic-drop" as I can think of, after noting in his 1993 lectures that Fermat's Last Theorem was a mere corollary of the work presented, Andrew Wiles famously [ended his lecture](https://wild.maths.org/andrew-wiles-and-fermats-last-theorem) by stating "I think I'll stop here."

> What are other noteworthy examples of such announcements in math that are, in some sense, memorable for being understated?  Say to an outsider in the field?

Cole's silent 1903 lecture factoring Mersenne prime $M_{67}$ would be a good contender, if it were actually true.  Watson and Crick's famous ending of their DNA paper, "It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material," has a bit of the same feel...