Question mark
The rhetorical question mark or percontation point was invented by Henry Denham in the 1580s and was used at the end of a rhetorical question; however, its use died out in the 17th century. It was later revived in modern-day society by Matt DiRoberto. It was the reverse of an ordinary question mark, so that instead of the main opening pointing back into the sentence, it opened away from it. This character can be represented using the reversed question mark (⸮) found in Unicode as U+2E2E. The percontation point is analogous to the irony mark, but those are even more rarely seen.
Hallmark
The control or inspection of precious metals was an ancient concept of examination and marking, by means of inspection stamps (punch marks). The use of hallmarks, at first on silver, has a long history dating back to the 4th century AD — there is evidence of silver bars marked under authority of the Emperor Augustinian around AD 350 — and represents the oldest known form of consumer protection. A series or system of five marks has been found on Byzantine silver dating from this period, though their interpretation is still not completely resolved.