oh snap, the coolness never ends

Chronogram:

A phrase, sentence, or inscription, in which certain letters (usually distinguished by size or otherwise from the rest) express by their numerical values a date or epoch.
‘Thus, in 1666, when a day of national humiliation was appointed in the expectation of an engagement between the English and Dutch navies, a pamphlet issued in reference to the fast-day, instead of bearing the imprint of the year after the usual fashion, had this seasonable sentence at the bottom of the title-page: ‘LorD haVe MerCIe Vpon Vs’. It will be seen that the total sum of the figures represented by the numeral letters (printed in capitals) gives the requisite date 1666’ (Athenæum No. 2868).

1621 BURTON Anat. Mel. II. ii. iv. (1676) 179/2 He may..make..Anagrams, Chronograms, Acrosticks upon his friends names. 1623 R. TISDALE (title), Pax Vobis. A Congratulatorie Poem..and some other Chronograms. 1640 SHIRLEY Humorous Court. II. ii, Now you can make chronograms. 1711 ADDISON Spect. No. 601 6. 1781 HARRIS Philol. Enquiries (1841) 520 Chronograms..were not confined to initial letters..the numeral letters, in whatever part of the word they stood, were distinguished from other letters by being written in capitals. 1882 J. HILTON Chronograms I. Pref. 5 The word Chronogram is said to have been first used in some verses addressed to the King of Poland in 1575. Ibid. Pref. 8 It is essential to a good chronogram that every numerical letter in the sentence must be counted.