The B with flourish is known principally from the works of Jesuit missionary Alexandre de Rhodes, particularly his trilingual dictionary Dictionarium Annamiticum Lusitanum et Latinum (1651) and bilingual Cathechismus (1658).

[1] The Vietnamese alphabet was formally described for the first time in the 17th-century text Manuductio ad Linguam Tunckinensem, attributed to a Portuguese Jesuit missionary, possibly Francisco de Pina[2] or Filipe Sibin.

[3] This passage about the letter Ꞗ was later incorporated into de Rhodes's Dictionarium:[4] …pronunciatur ferè ut β Græcum ut, ꞗĕaò ingredi, non eſt tamen omninò ſimile noſtro, V, conſonanti, ſed paulo aſperius, & in ipſa labiorum apertione pronuntiatur ita ut ſit verè litera labialis, ut Hebræi loquuntur, non autem dentalis.The passage roughly translates to: …pronounced almost like the Greek β, for example, ꞗĕaò, to enter, yet not quite the same as our consonant V, but a little coarser, and in the very opening of the lips pronounced, indeed, as though it was a labial letter, as the Hebrews speak it, rather than a dental.The linguistic interpretation of this description is that the sound was a voiced bilabial fricative, which phoneticians transcribe with the Greek letter beta [β].

[6] Although some peculiarities of de Rhodes's orthography persisted into the early 19th century,[7] the B with flourish had by then become V, as seen in the writings of Vietnamese Jesuit Philipphê Bỉnh (Philiphê do Rosario).

The lowercase B with flourish and a hypothetical uppercase form, unattested in de Rhodes's works, were standardized in June 2014 as part of the Latin Extended-D block of Unicode 7.0.