Question mark

In addition to its use to indicate interrogation, the question mark is used to indicate:

  • uncertainty in dates

1635?–1690

  • unknown alleles

Rps? (Harosoy) [an allele at an unknown locus]

AP-? (T160) [an unknown allele at the Ap locus]

Exclamation mark

In addition to its use to indicate strong feelings, an exclamation mark is used in science:

  • in botanical writing to indicate that the author has seen a designated specimen in a herbarium

Holotype: MEL! [specimen at Melbourne seen]

Isolectotypes: HO!, K. [specimen at Hobart seen, specimen at Kew not seen]

  • in maths as a factorial symbol

3! [means 3 × 2 × 1]